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The study investigated the elastic and inelastic scattering of 3He particles from 12C, 16O, 24Mg, and 28Si nuclei at 60 MeV using a double-folding approach with four newly derived effective nucleon-nucleon interactions (R3Y(HS), R3Y(L1), R3Y(W), and R3Y(Z)) derived from the relativistic mean-field (RMF) theory. The four derived effective NN interactions exhibited strong sensitivity to the choice of exchange potential. Regularizing NN interactions improved the agreement between calculated folded potentials and experimental data. Normalization constants for the R3Y(HS) interaction suggest its superiority over the R3Y(L1) and R3Y(W) interactions within the double-folding framework. Transition potentials based on two models, deformed potential and double folding potential, were used to describe inelastic scattering. Physically consistent deformation parameters were obtained. The deformed potential model yielded better results for 12C and 16O, whereas the double folding model performed better for 24Mg and 28Si, suggesting the double folding model's advantage is limited for lighter targets. The Bohr-Mottelson transition density effectively described 2+ states but was less suitable for the 3− state of 16O, for which a Tassie-like transition density provided improved agreement.
The study investigated the elastic and inelastic scattering of 3He particles from 12C, 16O, 24Mg, and 28Si nuclei at 60 MeV using a double-folding approach with four newly derived effective nucleon-nucleon interactions (R3Y(HS), R3Y(L1), R3Y(W), and R3Y(Z)) derived from the relativistic mean-field (RMF) theory. The four derived effective NN interactions exhibited strong sensitivity to the choice of exchange potential. Regularizing NN interactions improved the agreement between calculated folded potentials and experimental data. Normalization constants for the R3Y(HS) interaction suggest its superiority over the R3Y(L1) and R3Y(W) interactions within the double-folding framework. Transition potentials based on two models, deformed potential and double folding potential, were used to describe inelastic scattering. Physically consistent deformation parameters were obtained. The deformed potential model yielded better results for 12C and 16O, whereas the double folding model performed better for 24Mg and 28Si, suggesting the double folding model's advantage is limited for lighter targets. The Bohr-Mottelson transition density effectively described 2+ states but was less suitable for the 3− state of 16O, for which a Tassie-like transition density provided improved agreement.
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We study the inelastic charmonium (\begin{document}$ J/\psi $\end{document} ![]()
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, \begin{document}$ \psi(2S) $\end{document} ![]()
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) and bottomonium (\begin{document}$ \Upsilon(nS) $\end{document} ![]()
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) photoproduction and fragmentation processes in p-p and \begin{document}$ Pb $\end{document} ![]()
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-\begin{document}$ Pb $\end{document} ![]()
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collisions at LHC energies, where the ultra-incoherent photon emission is included. In the framework of the NRQCD factorization approach, an exact treatment is developed which recovers Weizsäcker-Williams approximation (WWA) near the region \begin{document}$ Q^{2}\sim0 $\end{document} ![]()
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, where the methods of Martin-Ryskin and BCCKL are used to avoid double counting. We calculate the \begin{document}$ Q^{2} $\end{document} ![]()
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, y, z, \begin{document}$ \sqrt{s} $\end{document} ![]()
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, \begin{document}$ p_{T} $\end{document} ![]()
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dependent and the total cross sections. It turns out that the inelastic photoproduction and fragmentation processes provide valuable contributions to the heavy quarkonium production, especially in the large \begin{document}$ p_{T} $\end{document} ![]()
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regions. While the relative contribution of ultra-incoherent photon channel is very important, which rapidly increases along with the growing quarkonium mass, and begins to dominate the photoproduction processes at large \begin{document}$ p_{T} $\end{document} ![]()
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ranges. Moreover, we obtain the complete validity scopes of WWA in inelastic heavy quarkonium photoproduction in heavy-ion collisions. WWA has a much higher accuracy at high energies and in \begin{document}$ Pb $\end{document} ![]()
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-\begin{document}$ Pb $\end{document} ![]()
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collisions. The existing photon spectra are generally derived beyond the applicable scopes of WWA, and the double counting exists when the different channels are considered simultaneously.
We study the inelastic charmonium (
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We present a comprehensive analysis of near-threshold photoproduction of\begin{document}$\rho^0$\end{document} ![]()
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, ω, and ϕ mesons on a deuterium target, utilizing published datasets from DESY and SLAC for \begin{document}$\rho^0$\end{document} ![]()
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and ω production, as well as data from the LEPS and CLAS Collaborations for ϕ production. In extracting the deuteron mass radius, we adopt a dipole parametrization for the scalar gravitational form factor, which effectively captures the \begin{document}$|t|$\end{document} ![]()
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-dependence of the differential cross sections associated with vector meson photoproduction. In addition, results from alternative commonly used form factor parametrizations are also considered and compared. Employing the vector meson dominance (VMD) framework and invoking low-energy Quantum Chromodynamics (QCD) theorems, we extract the deuteron mass radius from near-threshold photoproduction data of \begin{document}$\rho^0$\end{document} ![]()
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, ω, and ϕ mesons. The mass radii obtained from the various datasets are found to be consistent within statistical uncertainties, yielding an average value of \begin{document}$2.03 \pm 0.13$\end{document} ![]()
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fm under the dipole form assumption. We also provide a detailed discussion of the sensitivity of the extracted radius to different choices of gravitational form factor models. Our result represents a significant improvement in precision compared to earlier estimates based solely on ϕ meson photoproduction, offering new constraints for theoretical models of nuclear structure and deepening our understanding of the mass distribution within the deuteron.
We present a comprehensive analysis of near-threshold photoproduction of
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Application of the dynamical eikonal approximation(DEA) to elastic scattering for Coulomb-dominated reactions at low energy is studied. Our test case consists of elastic scattering for 8B, 9C and 11Be on 208Pb at 21.3, 25.2 and 12.7 MeV/nucleon, respectively. We introduce an empirical correction to the DEA method to account for Coulomb deflection, which significantly improves the description of elastic scattering of weakly-bound nuclei on heavy target. The angular distributions of elastic scattering obtained using the empirical correction show a good agreement with experimental data down to around 10 MeV/nucleon. Furthermore, we study the the effect of relativistic kinematics corrections on the angular distributions of elastic scattering at incident energies between 20 and 60 MeV/nucleon. The results show that relativistic kinematics corrections are crucial for describing the angular distributions of elastic scattering as low as around 40 MeV/nucleon.
Application of the dynamical eikonal approximation(DEA) to elastic scattering for Coulomb-dominated reactions at low energy is studied. Our test case consists of elastic scattering for 8B, 9C and 11Be on 208Pb at 21.3, 25.2 and 12.7 MeV/nucleon, respectively. We introduce an empirical correction to the DEA method to account for Coulomb deflection, which significantly improves the description of elastic scattering of weakly-bound nuclei on heavy target. The angular distributions of elastic scattering obtained using the empirical correction show a good agreement with experimental data down to around 10 MeV/nucleon. Furthermore, we study the the effect of relativistic kinematics corrections on the angular distributions of elastic scattering at incident energies between 20 and 60 MeV/nucleon. The results show that relativistic kinematics corrections are crucial for describing the angular distributions of elastic scattering as low as around 40 MeV/nucleon.
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In recent years, many studies on neutrino-nucleus scattering have been carried out to investigate nuclear structures and the interactions between neutrinos and nucleons. This paper develops a charged-current quasielastic (CCQE) neutrino-nucleus scattering model to explore the nuclear mean-field dynamics and short-range correlation effects. In this model, the nuclear structure effect is depicted using the scaling function\begin{document}$ f(\psi) $\end{document} ![]()
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, while the neutrino-nucleon interaction is represented by the elementary weak cross section \begin{document}$ \sigma_0 $\end{document} ![]()
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. Results indicate that the double-differential cross section of scattered muon is influenced by the energy \begin{document}$ E $\end{document} ![]()
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and momentum \begin{document}$ {\bf{p}} $\end{document} ![]()
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of nucleon in nuclei, and the total cross section depends primarily on the incident neutrino energy \begin{document}$ E_\nu $\end{document} ![]()
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. Furthermore, incorporating short-range correlations yields the flux-integrated differential cross sections at high-\begin{document}$ T_\mu $\end{document} ![]()
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region producing larger values, a longer tail, and achieving better experimental consistency. It eventually elucidates the physical relationship between the neutrino-nucleus scattering cross section and the variation in incident neutrino energy. The studies in this paper furnish insights for the research of nucleon dynamics and provides detailed examinations of the neutrino-nucleus scattering mechanism.
In recent years, many studies on neutrino-nucleus scattering have been carried out to investigate nuclear structures and the interactions between neutrinos and nucleons. This paper develops a charged-current quasielastic (CCQE) neutrino-nucleus scattering model to explore the nuclear mean-field dynamics and short-range correlation effects. In this model, the nuclear structure effect is depicted using the scaling function
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We present the solution of a non-linear magnetic-charged black hole with an anisotropic matter field and further extend it to obtain the corresponding rotating black hole solution using the modified Newman-Janis algorithm. The event horizon and ergosphere of the rotating black hole are studied in terms of the perspective of geometric properties, revealing that the rotating black hole can have up to three horizons. The first law of thermodynamics and the squared-mass formula for the rotating black hole are derived from a thermodynamic perspective, based on which we obtain the thermodynamic quantities and study the thermodynamic stability of the rotating black hole. Additionally, we calculate the Penrose process for the rotating black hole, indicating the influence of various black hole parameters on the maximal efficiency of the Penrose process.
We present the solution of a non-linear magnetic-charged black hole with an anisotropic matter field and further extend it to obtain the corresponding rotating black hole solution using the modified Newman-Janis algorithm. The event horizon and ergosphere of the rotating black hole are studied in terms of the perspective of geometric properties, revealing that the rotating black hole can have up to three horizons. The first law of thermodynamics and the squared-mass formula for the rotating black hole are derived from a thermodynamic perspective, based on which we obtain the thermodynamic quantities and study the thermodynamic stability of the rotating black hole. Additionally, we calculate the Penrose process for the rotating black hole, indicating the influence of various black hole parameters on the maximal efficiency of the Penrose process.
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The effect of electron-electron interaction on positron emission in supercritical collisions of highly charged ions is studied within the monopole approximation using the time-dependent density functional theory and the time-dependent Hartree–Fock–Slater methods. Positron production probabilities and energy spectra are calculated for U–U, U–Cm, and Cm–Cm collision systems, considering both bare nuclei and highly charged ions with partially filled electron shells. The results demonstrate that screening of the nuclear potential by electrons along with Pauli blocking substantially reduce positron production and suppress the characteristic signatures of spontaneous vacuum decay, previously found in collisions of bare nuclei.
The effect of electron-electron interaction on positron emission in supercritical collisions of highly charged ions is studied within the monopole approximation using the time-dependent density functional theory and the time-dependent Hartree–Fock–Slater methods. Positron production probabilities and energy spectra are calculated for U–U, U–Cm, and Cm–Cm collision systems, considering both bare nuclei and highly charged ions with partially filled electron shells. The results demonstrate that screening of the nuclear potential by electrons along with Pauli blocking substantially reduce positron production and suppress the characteristic signatures of spontaneous vacuum decay, previously found in collisions of bare nuclei.
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Lepton flavor violation (LFV) offers a powerful probe of physics beyond the Standard Model, particularly in models addressing neutrino masses and the baryon asymmetry of the universe. In this study, we investigate LFV processes within the framework of type II seesaw leptogenesis, where the Standard Model is extended by an\begin{document}$SU(2)_L$\end{document} ![]()
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triplet Higgs field. We focus on key LFV processes including \begin{document}$\mu^+\to e^+\gamma$\end{document} ![]()
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, \begin{document}$\mu^+ \to e^+e^-e^+$\end{document} ![]()
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, and \begin{document}$\mu \rightarrow e$\end{document} ![]()
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conversion in nuclei, deriving stringent constraints on the parameter space from current experimental data. We scan the 3σ range of neutrino oscillation parameters and identify the most conservative bounds consistent with existing measurements. Our results reveal that the MEG experiment currently provides the strongest constraints in the normal ordering (NO) scenario, while the SINDRUM experiment offers comparable sensitivity in the inverted ordering (IO) case. Future experiments, such as MEG II, Mu3e, Mu2e, and COMET, are predicted to significantly improve the sensitivity, testing larger regions of the parameter space.
Lepton flavor violation (LFV) offers a powerful probe of physics beyond the Standard Model, particularly in models addressing neutrino masses and the baryon asymmetry of the universe. In this study, we investigate LFV processes within the framework of type II seesaw leptogenesis, where the Standard Model is extended by an
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We investigate the shadows and optical appearances of a new type of regular black holes (BHs) with a Minkowski core under different spherical accretion. These BHs are constructed by modifying the Newtonian potential based on the minimum observable length in the Generalized Uncertainty Principle (GUP). They correspond one-to-one with the traditional regular BHs with a de-Sitter (dS) core (such as Bardeen/Hayward BHs), characterized by quantum gravity effect parameter (\begin{document}$ \alpha_0 $\end{document} ![]()
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) and spacetime deformation factor (n). We find that the characteristic parameters give rise to some novel observable features. For these new BHs, the shadow radius and the photon sphere radius decrease with the increase of \begin{document}$ \alpha_0 $\end{document} ![]()
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, while the observed specific intensity increases. Conversely, as n increases, the shadow radius and the photon sphere radius increase, whereas the observed specific intensity decreases. Under different spherical accretion, the shadows and the photon sphere radius are identical, but the observed specific intensity under the static spherical accretion is greater than that under the infalling spherical accretion. In addition, we find that these regular BHs with different cores show differences in shadows and optical appearances, especially under the static spherical accretion. Compared with Bardeen BH, the new BH has a smaller observed specific intensity, dimmer photon ring, and smaller shadow radius and photon sphere radius. The larger \begin{document}$ \alpha_0 $\end{document} ![]()
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leads to more significant differences, and a similar trend is also seen in the comparison with Hayward BH. Under the infalling spherical accretion, these regular BHs with different cores only have slight differences in observed specific intensity, which become more obvious when \begin{document}$ \alpha_0 $\end{document} ![]()
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is relatively large. It suggests that the unique spacetime features of these regular BHs with different cores can be distinguished through astronomical observations.
We investigate the shadows and optical appearances of a new type of regular black holes (BHs) with a Minkowski core under different spherical accretion. These BHs are constructed by modifying the Newtonian potential based on the minimum observable length in the Generalized Uncertainty Principle (GUP). They correspond one-to-one with the traditional regular BHs with a de-Sitter (dS) core (such as Bardeen/Hayward BHs), characterized by quantum gravity effect parameter (
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We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves. Specifically, we examine the case where this era originates from the dark matter dilution mechanism within the framework of the minimal left-right symmetric model. By numerically solving the Boltzmann equations governing the energy densities of the relevant components, we meticulously analyze the modifications to the cosmological scale factor, the number density of cosmic string loops, and the gravitational wave spectrum. Our results reveal that the early matter-dominated era causes a characteristic suppression in the high-frequency regime of the gravitational wave spectrum, providing distinct and testable signatures for future ground-based interferometer experiments.
We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves. Specifically, we examine the case where this era originates from the dark matter dilution mechanism within the framework of the minimal left-right symmetric model. By numerically solving the Boltzmann equations governing the energy densities of the relevant components, we meticulously analyze the modifications to the cosmological scale factor, the number density of cosmic string loops, and the gravitational wave spectrum. Our results reveal that the early matter-dominated era causes a characteristic suppression in the high-frequency regime of the gravitational wave spectrum, providing distinct and testable signatures for future ground-based interferometer experiments.
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Recent years have seen the development and growth of machine learning in high energy physics. There will be more effort to continue exploring its full potential. To make it easier for researchers to apply existing algorithms and neural networks and to advance the reproducibility of the analysis, we develop the HEP ML LAB (\begin{document}$ \mathrm{hml}$\end{document} ![]()
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), a Python-based, end-to-end framework for phenomenology studies. It covers the complete workflow from event generation to performance evaluation, and provides a consistent style of use for different approaches. We propose an observable naming convention to streamline the data extraction and conversion processes. In the KERAS style, we provide the traditional cut-and-count and boosted decision trees together with neural networks. We take the $W^+$ tagging as an example and evaluate all built-in approaches with the metrics of significance and background rejection. With its modular design, HEP ML LAB is easy to extend and customize, and can be used as a tool for both beginners and experienced researchers.
Recent years have seen the development and growth of machine learning in high energy physics. There will be more effort to continue exploring its full potential. To make it easier for researchers to apply existing algorithms and neural networks and to advance the reproducibility of the analysis, we develop the HEP ML LAB (
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We consider two-loop planar contributions to a three-body form factor at the next-to-leading power in the high-energy limit, where the masses of external particles are much smaller than their energies. The calculation is performed by exploiting the differential equations of the expansion coefficients, both for facilitating the linear relations among them, and for deriving their analytic expressions. The result is written in terms of generalized polylogarithms involving a few simple symbol letters. Our method can be readily applied to the calculation of non-planar contributions as well. The result provides crucial information for establishing sub-leading factorization theorems for massive scattering amplitudes in the high-energy limit.
We consider two-loop planar contributions to a three-body form factor at the next-to-leading power in the high-energy limit, where the masses of external particles are much smaller than their energies. The calculation is performed by exploiting the differential equations of the expansion coefficients, both for facilitating the linear relations among them, and for deriving their analytic expressions. The result is written in terms of generalized polylogarithms involving a few simple symbol letters. Our method can be readily applied to the calculation of non-planar contributions as well. The result provides crucial information for establishing sub-leading factorization theorems for massive scattering amplitudes in the high-energy limit.
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The α-decay half-lives of superheavy nuclei (SHN) with charge number Z≥104 are investigated by employing a phenomenological one-parameter model based on the quantum-mechanical tunneling through a potential barrier where both the centrifugal and overlapping effects have been taken into account. It is shown that the experimental α-decay half-lives of the 81 SHN are reproduced well. Moreover, the order of magnitude for the α-particle preformation probability inside a parent nucleus (\begin{document}$S _{\alpha } $\end{document} ![]()
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) is found as \begin{document}$ 10^{-2} $\end{document} ![]()
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. Then, within this model, the \begin{document}$S _{\alpha } $\end{document} ![]()
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values and α-decay half-lives of Z = 118-120 isotopes are predicted by inputting the α-decay energies (\begin{document}$ Q_{\alpha } $\end{document} ![]()
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) extracted from the relativistic continuum Hartree-Bogoliubov (RCHB) theory, Duflo-Zuker 19 (DZ19, here 19 denotes the numbers of the fitting parameters.) model, improved Weizsacker-Skyrme (IMWS) model and machine learning (ML) approach, respectively. By analyzing the evolutions of \begin{document}$ Q_{\alpha } $\end{document} ![]()
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, \begin{document}$S _{\alpha } $\end{document} ![]()
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and α-decay half-lives of Z = 118-120 isotopes with the neutron number N of the parent nucleus, it is found that the shell effect at N = 184 are evident for all the nuclear mass models. Meanwhile, for the case of the RCHB, N = 172 is determined as a submagic number. However, the submagic number at N = 172 is replaced by N = 178 for the ML approach.
The α-decay half-lives of superheavy nuclei (SHN) with charge number Z≥104 are investigated by employing a phenomenological one-parameter model based on the quantum-mechanical tunneling through a potential barrier where both the centrifugal and overlapping effects have been taken into account. It is shown that the experimental α-decay half-lives of the 81 SHN are reproduced well. Moreover, the order of magnitude for the α-particle preformation probability inside a parent nucleus (
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A horizonless ultracompact object can have a stable antiphoton sphere, which causes the strong deflection of photons inside the unstable photon sphere, leading to the formation of distinctive inner photon rings. In this work, we present analytical descriptions for the shape, thickness and interference pattern of higher-order inner photon rings. By taking the static spherically symmetric Schwarzschild star with a photon sphere as an example, we find that its inner photon rings can be more non-circular and thicker than the outer ones, and show that the inclusion of the inner photon rings can give rise to new features in the interferometric pattern. Our formulae can also be applied to other ultracompact objects, providing a convenient way to study the observational properties of their higher-order photon rings.
A horizonless ultracompact object can have a stable antiphoton sphere, which causes the strong deflection of photons inside the unstable photon sphere, leading to the formation of distinctive inner photon rings. In this work, we present analytical descriptions for the shape, thickness and interference pattern of higher-order inner photon rings. By taking the static spherically symmetric Schwarzschild star with a photon sphere as an example, we find that its inner photon rings can be more non-circular and thicker than the outer ones, and show that the inclusion of the inner photon rings can give rise to new features in the interferometric pattern. Our formulae can also be applied to other ultracompact objects, providing a convenient way to study the observational properties of their higher-order photon rings.
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The formalism for a quantitative treatment of high-momentum components of\begin{document}$ NN $\end{document} ![]()
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momentum distributions for the spin-singlet channels is presented. The approach suggests the use of a distribution for a virtual state in momentum representation for the \begin{document}$ NN $\end{document} ![]()
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channel in question as a universal one which can be further employed within contact formalisms for nuclei. It is shown how such distributions can be calculated from low-energy scattering wave functions in the same channels. As a result, a new characteristic (a constant) for the high-momentum part of the momentum distribution in a spin-singlet channel is introduced. As a test of the approach, we calculate the \begin{document}$ pp $\end{document} ![]()
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nuclear contacts for \begin{document}$ ^3 {\rm{He}}$\end{document} ![]()
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nucleus which occur to be nearly the same for four realistic \begin{document}$ NN $\end{document} ![]()
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interactions with essentially different high-momentum properties. Found results should be useful for researchers studying the problem of short-range correlations in nuclei. In particular, the approach gives a generalization for the formalisms based on nuclear contacts.
The formalism for a quantitative treatment of high-momentum components of
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This study investigates a black hole surrounded by a cloud of strings and a cosmological dark fluid characterized by a modified Chaplygin-like equation of state (MCDF),\begin{document}$ p=A\rho-B/\rho^{\beta} $\end{document} ![]()
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. We analyze its geodesic structure, shadow, and optical appearance. Analysis of the effective potential and epicyclic frequencies reveals that the existence of innermost/outermost stable circular orbits (ISCOs/OSCOs) for timelike particles is controlled by the parameters of the MCDF and the cloud of strings. The behavior of orbital conserved quantities and the Keplerian frequency are also examined. By equating the influence of the MCDF on the spacetime metric at spatial infinity with that of a cosmological constant, we constrain the MCDF parameters using the observed shadow radii of Sgr A* and M87*. We investigate the effects of the cloud of strings and MCDF on the black hole's shadows and optical images, assuming various thin disk accretion profiles. Using the method developed by Wald and collaborators, light trajectories are classified by their impact parameters into direct emission, the lensing ring, and the photon ring. The presence of OSCOs can lead to the existence of outer edges in the direct emission and lensing ring images. Observed brightness primarily originates from direct emission, with a minor contribution from the lensing ring, while the photon ring's contribution is negligible due to extreme demagnification. The influence of the cloud of strings and MCDF parameters on all results is analyzed throughout the study.
This study investigates a black hole surrounded by a cloud of strings and a cosmological dark fluid characterized by a modified Chaplygin-like equation of state (MCDF),
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Physics-Informed Neural Networks (PINNs) have emerged as a powerful tool for solving high-dimensional partial differential equations, demonstrating promising results across various fields of physics and engineering. In this study, We present the first application of PINNs to quantum tunneling in heavy-ion fusion reactions. By incorporating the physical laws directly into the neural network's loss function, PINNs enable the accurate solution of the multidimensional Schrödinger equation, whose wavefunction has substantial oscillations. The calculated quantum tunneling probabilities exhibit well agreement with those obtained using the finite element method at the considered near barrier energy region. Furthermore, we demonstrate a significant advantage of the PINN approach to save and fine-tune pre-trained neural networks for related tunneling calculations, thereby enhancing computational efficiency and adaptability.
Physics-Informed Neural Networks (PINNs) have emerged as a powerful tool for solving high-dimensional partial differential equations, demonstrating promising results across various fields of physics and engineering. In this study, We present the first application of PINNs to quantum tunneling in heavy-ion fusion reactions. By incorporating the physical laws directly into the neural network's loss function, PINNs enable the accurate solution of the multidimensional Schrödinger equation, whose wavefunction has substantial oscillations. The calculated quantum tunneling probabilities exhibit well agreement with those obtained using the finite element method at the considered near barrier energy region. Furthermore, we demonstrate a significant advantage of the PINN approach to save and fine-tune pre-trained neural networks for related tunneling calculations, thereby enhancing computational efficiency and adaptability.
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We constrain the symmetry energy slope L at the saturation density using the neutron skin values of 48Ca, 64Ni, 124Sn, and 208Pb determined by various experiments. The resulting L of 50(6) MeV is consistent with the world-averaged value from different observables and methodologies. Furthermore, the implications of newly constrained L on the radius determinations of 1.4 solar-mass neutron stars are also discussed based on the established\begin{document}$ R_{1.4}$\end{document} ![]()
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-L linear relationships by the DD-ME2 and TW99 EoS families.
We constrain the symmetry energy slope L at the saturation density using the neutron skin values of 48Ca, 64Ni, 124Sn, and 208Pb determined by various experiments. The resulting L of 50(6) MeV is consistent with the world-averaged value from different observables and methodologies. Furthermore, the implications of newly constrained L on the radius determinations of 1.4 solar-mass neutron stars are also discussed based on the established
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Based on the extended projected shell model – a microscopic nuclear many-body theory – we have revealed an unexpected phenomenon (\begin{document}$ \Delta I = 2 $\end{document} ![]()
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bifurcation) in rotational bands associated with scissors vibrations in \begin{document}$ ^{156} {\rm{Gd}}$\end{document} ![]()
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in our recently published article [Phys. Rev. Lett. 129, 042502 (2022)]. In the present work, we extended the study by systematically changing the model parameters (deformation and strength of the monopole-pairing force) for the \begin{document}$ ^{156} {\rm{Gd}}$\end{document} ![]()
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calculation. We also calculated additional isotopes and isotones with respect to \begin{document}$ ^{156} {\rm{Gd}}$\end{document} ![]()
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. In all calculations, we found a similar occurrence of the \begin{document}$ \Delta I = 2 $\end{document} ![]()
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bifurcation in the results. We thus confirmed that the bifurcation behavior of the scissors' rotation bands originates from the self-organizing effects of deformed proton and neutron bodies during the scissors motion, independently of the model parameters.
Based on the extended projected shell model – a microscopic nuclear many-body theory – we have revealed an unexpected phenomenon (
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This study explores the thermodynamics, quantum tunneling phenomena, and unique orbital properties of Einstein-Power-Yang-Mills (EPYM) black holes embedded in Anti-de Sitter (AdS) spacetimes, highlighting the role of the nonlinear Yang-Mills (YM) charge parameter γ. We derive explicit expressions for the black hole metric, horizon structure, and associated thermodynamic quantities, including Hawking temperature and phase transitions. Using the WKB approximation and Hamilton-Jacobi formalism, we investigate the quantum tunneling of massive\begin{document}$ W^+ $\end{document} ![]()
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bosons, revealing how nonlinear YM interactions significantly alter the radiation spectrum and emission rates. We analyze the effective potential for scalar field propagation, showing that nonlinear YM effects produce distinctive modifications in potential barriers and radiation emission processes. Additionally, our study uncovers the presence of the Aschenbach effect, typically exclusive to rotating black holes, in static and spherically symmetric EPYM black hole solutions.
This study explores the thermodynamics, quantum tunneling phenomena, and unique orbital properties of Einstein-Power-Yang-Mills (EPYM) black holes embedded in Anti-de Sitter (AdS) spacetimes, highlighting the role of the nonlinear Yang-Mills (YM) charge parameter γ. We derive explicit expressions for the black hole metric, horizon structure, and associated thermodynamic quantities, including Hawking temperature and phase transitions. Using the WKB approximation and Hamilton-Jacobi formalism, we investigate the quantum tunneling of massive
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The production, dynamic evolution, and decay of\begin{document}$ \Delta $\end{document} ![]()
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particles play a crucial role in understanding the properties of high baryon density nuclear matter in intermediate-energy heavy-ion collisions. In this work, the energy-, density-, and isospin-dependent nucleon-\begin{document}$ \Delta $\end{document} ![]()
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elastic cross section (\begin{document}$ \sigma^{*}_{N \Delta} $\end{document} ![]()
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) is studied within the framework of the relativistic Boltzmann-Uehling-Uhlenbeck transport theory, in which the \begin{document}$ \delta $\end{document} ![]()
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meson field is further considered beside the \begin{document}$ \sigma $\end{document} ![]()
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, \begin{document}$ \omega $\end{document} ![]()
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, and \begin{document}$ \rho $\end{document} ![]()
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meson fields. The results show that the \begin{document}$ \delta $\end{document} ![]()
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and \begin{document}$ \rho $\end{document} ![]()
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meson related exchange terms have a nonnegligible contribution to the \begin{document}$ \sigma^{*}_{N \Delta} $\end{document} ![]()
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compared to only considering the \begin{document}$ \rho $\end{document} ![]()
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meson exchange terms, although there is a significant cancellation on the cross section among these meson exchange terms. In addition, due to the different effects of the medium correction on the effective mass of neutrons, protons, and differently charged \begin{document}$ \Delta $\end{document} ![]()
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s, the individual \begin{document}$ \sigma^{*}_{N \Delta} $\end{document} ![]()
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exhibits an ordered isospin-asymmetry (\begin{document}$ \alpha $\end{document} ![]()
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) dependence, and \begin{document}$ \sigma^{*}_{n\Delta} $\end{document} ![]()
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and \begin{document}$ \sigma^{*}_{p\Delta} $\end{document} ![]()
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have opposite \begin{document}$ \alpha $\end{document} ![]()
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dependencies. And the \begin{document}$ \alpha $\end{document} ![]()
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dependence of the ratio \begin{document}$ R(\alpha)=\sigma^{*}(\alpha)/\sigma^{*}(\alpha=0) $\end{document} ![]()
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for \begin{document}$ n\Delta $\end{document} ![]()
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reaction channels follow \begin{document}$ n\Delta^{++}>n\Delta^{+}>n\Delta^{0}>n\Delta^{-} $\end{document} ![]()
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, while for \begin{document}$ p\Delta $\end{document} ![]()
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it is \begin{document}$ p\Delta^{-}>p\Delta^{0}>p\Delta^{+}>p\Delta^{++} $\end{document} ![]()
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. Moreover, the results also indicate that the isospin effect on the \begin{document}$ \sigma^{*}_{N \Delta} $\end{document} ![]()
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, which is dominantly caused by the isovector \begin{document}$ \rho $\end{document} ![]()
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and \begin{document}$ \delta $\end{document} ![]()
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meson fields, is still pronounced at densities up to 3 times normal nuclear density. Finally, a parametrization of the energy-, density-, and isospin-dependent \begin{document}$ N\Delta $\end{document} ![]()
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elastic cross section is proposed based on the microscopic calculated results, and the in-medium \begin{document}$ \sigma^{*}_{N \Delta} $\end{document} ![]()
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in the energy range of \begin{document}$ \sqrt{s} $\end{document} ![]()
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=2.3~3.0 GeV can be well described.
The production, dynamic evolution, and decay of
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In this work, we extend our previous work on the\begin{document}$ D^*\bar{D}^* $\end{document} ![]()
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molecular states with the \begin{document}$ J^{PC}=0^{++} $\end{document} ![]()
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, \begin{document}$ 1^{+-} $\end{document} ![]()
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and \begin{document}$ 2^{++} $\end{document} ![]()
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to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We obtain the partial decay widths therefore total widths of the ground states with the \begin{document}$ J^{PC}=0^{++} $\end{document} ![]()
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, \begin{document}$ 1^{+-} $\end{document} ![]()
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and \begin{document}$ 2^{++} $\end{document} ![]()
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, which indicate that it is reasonable to assign the \begin{document}$ X_2(4014) $\end{document} ![]()
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as the \begin{document}$ D^*\bar{D}^* $\end{document} ![]()
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tetraquark molecular states with the \begin{document}$ J^{PC}=2^{++} $\end{document} ![]()
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.
In this work, we extend our previous work on the
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The deformation driving tendency of various single particle orbitals near the Fermi surface has been investigated with the lifetime measurements of high spin states in the non-yrast bands of\begin{document}$^{177}Re$\end{document} ![]()
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nucleus. For this study, the \begin{document}$^{165}{\rm{Ho}}$\end{document} ![]()
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(\begin{document}$^{16}{\rm{O}}$\end{document} ![]()
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, 4n)\begin{document}$^{177}{\rm{Re}}$\end{document} ![]()
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reaction at a beam energy of 84 MeV was used. In the measurement, the lifetimes of four lowest levels of \begin{document}$\pi i_{13/2}[660]1/2^+$\end{document} ![]()
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band and four levels of \begin{document}$\pi d_{5/2}[402]5/2^+$\end{document} ![]()
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(α = -1/2) band have been obtained. The extracted transition quadrupole moments for the \begin{document}$\pi i_{13/2}$\end{document} ![]()
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intruder band show a sharp increase with increasing level spin, indicating a major shape transition happening in this nucleus. The average transitional quadrupole moment (\begin{document}${\rm{Q}}_t$\end{document} ![]()
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), a measure of deformation, for the \begin{document}$\pi i_{13/2}$\end{document} ![]()
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band is found to significantly larger (\begin{document}${\rm{Q}}_t$\end{document} ![]()
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~ 8.7 (6) eb) than for the \begin{document}$\pi d_{5/2}$\end{document} ![]()
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(\begin{document}${\rm{Q}}_t$\end{document} ![]()
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~ 6.3 (5) eb) band. To interpret the observed shape changes happening in the two bands, the experimental transition probabilities for these bands are compared with the results obtained from Projected Shell Model (PSM) calculations.
The deformation driving tendency of various single particle orbitals near the Fermi surface has been investigated with the lifetime measurements of high spin states in the non-yrast bands of
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Nuclear reaction studies on unstable isotopes can strongly help in improving our understanding of nucleosynthesis in stars. Indirect approaches to determining astrophysical reaction rates are increasingly common-place and undergoing continuous refinement. Of particular interest is the use of such indirect techniques at storage rings, which, among other allow to recycle rare unstable beams. We propose to investigate reaction rates of astrophysical interest using indirect methods (surrogate, Trojan horse….) in reverse kinematics at the IMP-CAS storage ring. Long lived radioactive ion beams, produced remotely, can be accelerated, and made interacting with light targets. Proposed reactions are 85Kr(p,p’γ), 85Kr(d,pγ), constraining the neutron flux in an s-process branching point, 79Se(p,p’γ), 79Se(d,pγ), constraining the temperature in s-process nucleosyntheses, 59Fe(d,pγ), constraining core collapse supernovae.
Nuclear reaction studies on unstable isotopes can strongly help in improving our understanding of nucleosynthesis in stars. Indirect approaches to determining astrophysical reaction rates are increasingly common-place and undergoing continuous refinement. Of particular interest is the use of such indirect techniques at storage rings, which, among other allow to recycle rare unstable beams. We propose to investigate reaction rates of astrophysical interest using indirect methods (surrogate, Trojan horse….) in reverse kinematics at the IMP-CAS storage ring. Long lived radioactive ion beams, produced remotely, can be accelerated, and made interacting with light targets. Proposed reactions are 85Kr(p,p’γ), 85Kr(d,pγ), constraining the neutron flux in an s-process branching point, 79Se(p,p’γ), 79Se(d,pγ), constraining the temperature in s-process nucleosyntheses, 59Fe(d,pγ), constraining core collapse supernovae.
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Within the framework of the perturbative QCD approach utilizing\begin{document}$k_T$\end{document} ![]()
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factorization, we have investigated the CP violation and branching ratios in the decay processes of \begin{document}$B_{c}^{+}\to D_{(s)} ^{+}V(V\rightarrow\pi^{+}\pi^{-})$\end{document} ![]()
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and \begin{document}$B_{c}^{+}\to D_{(s)}^{+}V(V\rightarrow K^{+}K^{-})$\end{document} ![]()
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, where V denotes the three vector mesons \begin{document}$\rho^0$\end{document} ![]()
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, ω, and ϕ. During the \begin{document}$V\to \pi^+\pi^-$\end{document} ![]()
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and \begin{document}$V\to K^+K^-$\end{document} ![]()
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decay processes, we incorporated the \begin{document}$\rho^{0}-\omega-\phi$\end{document} ![]()
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mixing mechanism to describe the amplitudes of these quasi-two-body decays. Within the interference region of the three vector particles, we observed distinct changes in both CP violations and branching ratios. Furthermore, our study presents evidence for local CP violations and branching ratios that warrants further investigation through experiments.
Within the framework of the perturbative QCD approach utilizing
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Recent parameterizations of parton distribution functions (PDFs) have led to the determination of the gravitional form factors of the nucleon's dependence on generalized parton distributions of nucleons in the limit\begin{document}$\xi \to 0 $\end{document} ![]()
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. This paper aims to obtain the flavor division of nucleon electromagnetic and gravitional form factors using the VS24 Ansatz and two PDFs at \begin{document}$ N^3L0 $\end{document} ![]()
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approximation in GPDs. The PDFs and GPDs formalism enable the calculation of various form factors of nucleons in different approximations, as well as the calculation of the electric radius of nucleons. The study, despite its high approximation complexity, enhances the accuracy of calculations and brings them closer to the experimental values.
Recent parameterizations of parton distribution functions (PDFs) have led to the determination of the gravitional form factors of the nucleon's dependence on generalized parton distributions of nucleons in the limit
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The effects of nucleon-nucleon short-range correlations lead to the high-momentum tail (HMT) in the nucleon momentum distribution, is displayed by the isospin- and momentum-dependent Lanzhou quantum molecular dynamics (LQMD) transport model. Based on the transport model, we studied the effects of the HMT of nucleon momentum distribution in initialization in isotopic nuclear reactions at a beam energy of 120 MeV/u. The single and double ratios of gas-phase neutron and proton spectra are analyzed and compared with experimental data in central\begin{document}$ ^{112} {\rm{Sn}}$\end{document} ![]()
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+\begin{document}$ ^{112} {\rm{Sn}}$\end{document} ![]()
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and \begin{document}$ ^{124} {\rm{Sn}}$\end{document} ![]()
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+\begin{document}$ ^{124} {\rm{Sn}}$\end{document} ![]()
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collisions. The HMT affects the single ratios but not the double ratios that can be employed to study other isospin effects more effectively. The ratio of triton and \begin{document}$ ^3 {\rm{He}}$\end{document} ![]()
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of light clusters contained in the gas-phase nucleons is certainly also influenced by HMT. Combining with the QMD transport model that can describe multi-fragmentation and the production of fragments in intermediate-energy heavy-ion collisions, we have studied the short-range correlation effect on fragments generation. It is found that the isospin-dependent high-momentum tail evidently affects the fragment multiplicity distribution and the average neutron to proton ratio of produced isobars.
The effects of nucleon-nucleon short-range correlations lead to the high-momentum tail (HMT) in the nucleon momentum distribution, is displayed by the isospin- and momentum-dependent Lanzhou quantum molecular dynamics (LQMD) transport model. Based on the transport model, we studied the effects of the HMT of nucleon momentum distribution in initialization in isotopic nuclear reactions at a beam energy of 120 MeV/u. The single and double ratios of gas-phase neutron and proton spectra are analyzed and compared with experimental data in central
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, doi: 10.1088/1674-1137/add25e
Abstract:
In this study, we investigate the impact of rotation on the thermodynamic characteristics of QCD matter using the three-flavor NJL model. We examine the temperature, quark chemical potential, and angular velocity dependencies of key thermodynamic quantities, such as the trace anomaly, specific heat, speed of sound, angular momentum, and moment of inertia. As the main finding of our analysis, we observe that the speed of sound exhibits a nonmonotonic behavior as the angular velocity changes.
In this study, we investigate the impact of rotation on the thermodynamic characteristics of QCD matter using the three-flavor NJL model. We examine the temperature, quark chemical potential, and angular velocity dependencies of key thermodynamic quantities, such as the trace anomaly, specific heat, speed of sound, angular momentum, and moment of inertia. As the main finding of our analysis, we observe that the speed of sound exhibits a nonmonotonic behavior as the angular velocity changes.
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Fox-Wolfram Moments (FWMs) are a set of event shape observables that characterize the angular distribution of energy flow in high-energy collisions. In this work, we present the first theoretical investigation of FWMs for multi-jet production in relativistic heavy ion collisions. In this work, jet productions in p+p collisions are computed with a Monte Carlo event generator SHERPA, while the Linear Boltzmann Transport model is utilized to simulate the multiple scattering of energetic partons in the hot and dense QCD matter. The event-normalized distributions of the lower-order FWM,\begin{document}$H_1^T$\end{document} ![]()
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in p+p and Pb+Pb collisions are calculated. It is found that for events with jet number \begin{document}$n_\text{jet} = 2$\end{document} ![]()
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the \begin{document}$H_1^T$\end{document} ![]()
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distribution in Pb+Pb is suppressed at small \begin{document}$H_1^T$\end{document} ![]()
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while enhanced at large \begin{document}$H_1^T$\end{document} ![]()
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region as compared to p+p. For events with \begin{document}$n_\text{jet}>2$\end{document} ![]()
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, the jet number reduction effect due to jet quenching in the QGP decreases the \begin{document}$H_1^T$\end{document} ![]()
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distribution at large \begin{document}$H_1^T$\end{document} ![]()
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in Pb+Pb relative to p+p. The medium modification of the Fox-Wolfram moment \begin{document}$H_1^T$\end{document} ![]()
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for events with \begin{document}$n_\text{jet}\ge 2$\end{document} ![]()
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are also presented, which resemble those of events with \begin{document}$n_\text{jet} = 2$\end{document} ![]()
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. Its reason is revealed through the relative contribution fractions of events with different final-state jet numbers to \begin{document}$H_1^T$\end{document} ![]()
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.
Fox-Wolfram Moments (FWMs) are a set of event shape observables that characterize the angular distribution of energy flow in high-energy collisions. In this work, we present the first theoretical investigation of FWMs for multi-jet production in relativistic heavy ion collisions. In this work, jet productions in p+p collisions are computed with a Monte Carlo event generator SHERPA, while the Linear Boltzmann Transport model is utilized to simulate the multiple scattering of energetic partons in the hot and dense QCD matter. The event-normalized distributions of the lower-order FWM,
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Highly linear correlation between the charge radii difference of mirror-pair nuclei and the slope parameter of symmetry energy has been built in the existing literatures. In this work, the impact of neutron-proton correlation deduced from the neutron- and proton-pairs condensation around the Fermi surface on determining the slope parameter of nuclear symmetry energy is investigated based on the Skyrme density functionals. The differential charge radii of Ni isotopes are employed to inspect the validity of this recently developed model. The calculated results suggest that the modified model can reproduce the shell quenching of charge radii at the neutron number\begin{document}$ N=28 $\end{document} ![]()
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along Ni isotopic chain. The shell closure effect of the charge radii can also be predicted at the neutron number \begin{document}$ N=50 $\end{document} ![]()
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. The correlations between the charge radii differences of mirror partner nuclei 32Ar-32Si and 54Ni-54Fe and the slope parameters of symmetry energy are also analyzed. It is shown that the covered range of the symmetry energy slope is influenced by the neutron-pairs condensation around the Fermi surface. Moreover, a relatively stiff equation of state can be inferred from the mirror pairs 32Ar-32Si and 54Ni-54Fe when the influence coming from the neutron-pairs condensation is taken into account.
Highly linear correlation between the charge radii difference of mirror-pair nuclei and the slope parameter of symmetry energy has been built in the existing literatures. In this work, the impact of neutron-proton correlation deduced from the neutron- and proton-pairs condensation around the Fermi surface on determining the slope parameter of nuclear symmetry energy is investigated based on the Skyrme density functionals. The differential charge radii of Ni isotopes are employed to inspect the validity of this recently developed model. The calculated results suggest that the modified model can reproduce the shell quenching of charge radii at the neutron number
The lepton-number-violating pion decay and the type-I seesaw mechanism in chiral perturbation theory

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We investigate the process of lepton-number-violating pion decay, which dominates the nuclear neutrinoless double beta decay induced by the short-range operator, within the type-I seesaw mechanism. The type-I seesaw mechanism gives rise to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are usually called sterile neutrinos. Using chiral perturbation theory, the transition amplitudes in the case of the light and heavy sterile neutrinos are calculated up to\begin{document}$ \mathcal{O}(Q^2/\Lambda^2_\chi) $\end{document} ![]()
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respectively, where Q is the typical low-energy scale in this process and \begin{document}$ \Lambda_\chi $\end{document} ![]()
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the chiral symmetry breaking scale. We then adopt a naive interpolation formula of mass dependence to obtain the amplitude in the full mass range and briefly discuss its validity.
We investigate the process of lepton-number-violating pion decay, which dominates the nuclear neutrinoless double beta decay induced by the short-range operator, within the type-I seesaw mechanism. The type-I seesaw mechanism gives rise to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are usually called sterile neutrinos. Using chiral perturbation theory, the transition amplitudes in the case of the light and heavy sterile neutrinos are calculated up to
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Shell evolution is crucial for understanding nuclear structures across the nuclear chart. In this work, we employed the ab initio valence space in-medium similarity renormalization group with chiral nucleon-nucleon and three-nucleon interactions to study neutron-rich Si, S, Ar, and Ca isotopes, particularly focusing on nuclei near\begin{document}$ N=32, 34 $\end{document} ![]()
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. We systematically analyzed both neutron and proton shell evolutions by examining the excitation energies of the first \begin{document}$ 2^+ $\end{document} ![]()
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states and the effective single-particle energies. Our calculations show that the \begin{document}$ N=32 $\end{document} ![]()
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sub-shell gradually weakens as protons are removed from the doubly magic nucleus \begin{document}$ ^{52} {\rm{Ca}}$\end{document} ![]()
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, eventually disappearing in \begin{document}$ ^{46} {\rm{Si}}$\end{document} ![]()
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. Conversely, the strength of the \begin{document}$ N=34 $\end{document} ![]()
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sub-shell is enhanced with the removal of protons from \begin{document}$ ^{54} {\rm{Ca}}$\end{document} ![]()
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. Furthermore, our results indicate the existence of the proton \begin{document}$ Z=14 $\end{document} ![]()
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sub-shell in neutron-rich Si isotopes. These findings suggest that \begin{document}$ ^{48} {\rm{Si}}$\end{document} ![]()
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is a doubly magic nucleus, with the excitation energy of the first \begin{document}$ 2^+ $\end{document} ![]()
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state around 2.49 MeV, which is about 400 keV higher than that of \begin{document}$ ^{54} {\rm{Ca}}$\end{document} ![]()
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. This value is comparable to that of other well-known exotic doubly magic nuclei, such as \begin{document}$ ^{52} {\rm{Ca}}$\end{document} ![]()
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and \begin{document}$ ^{78} {\rm{Ni}}$\end{document} ![]()
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, which is extremely interesting for further experiments in RIB facilities. In addition, we predicted the low-lying spectra of neutron-rich Si, S, and Ar isotopes, providing new insights for future experiments.
Shell evolution is crucial for understanding nuclear structures across the nuclear chart. In this work, we employed the ab initio valence space in-medium similarity renormalization group with chiral nucleon-nucleon and three-nucleon interactions to study neutron-rich Si, S, Ar, and Ca isotopes, particularly focusing on nuclei near
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In this paper, we study the production of doubly charmed baryon from anti-bottom charmed meson. Using the effective Lagrangian approach, we discuss triangle diagrams in hadronic level to get access to the branching ratios of\begin{document}$\overline{B}_c\to {\cal{B}}_{ccq}+{\cal{B}}_{\bar c\bar q\bar q}$\end{document} ![]()
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. It seems that the specific process \begin{document}$\overline {B}_c \to \Xi_{cc}^{+} \, \overline {\Xi}_{\bar c}^{'0}$\end{document} ![]()
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occupies the largest possibility in the order of \begin{document}$9.1\times 10^{-5}$\end{document} ![]()
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. In addition, although the production of undiscovered \begin{document}$\Omega_{cc}^+$\end{document} ![]()
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is Cabibbo suppressed in \begin{document}$\overline B_c\to \Omega_{cc}^+ \, \overline {\Xi}_{\bar c}^0$\end{document} ![]()
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, it's branching ratio can still reach \begin{document}$10^{-7}$\end{document} ![]()
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level. These results are excepted to be fairly valuable supports for future experiments.
In this paper, we study the production of doubly charmed baryon from anti-bottom charmed meson. Using the effective Lagrangian approach, we discuss triangle diagrams in hadronic level to get access to the branching ratios of
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We study the\begin{document}$ \cos2\phi $\end{document} ![]()
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azimuthal asymmetry in doubly longitudinally polarized proton-proton Drell-Yan collisions within the transverse momentum dependent factorization framework. The asymmetry arises from the convolution of the longitudinal transversity distribution \begin{document}$ h_{1L}^{\perp} $\end{document} ![]()
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for both protons. Using the Bacchetta-Delcarro-Pisano-Radici-Signori parametrization for the nonperturbative Sudakov form factor and the Wandzura-Wilczek approximation for the collinear \begin{document}$ h_{1L}^{\perp} $\end{document} ![]()
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, we predict the double spin asymmetry \begin{document}$ A_{LL}^{\cos2\phi} $\end{document} ![]()
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at RHIC and NICA kinematics. Our results demonstrate sensitivity to sea quark distributions, with the asymmetry reaching up to 25% for maximal sea quark contributions. These predictions highlight the potential of polarized Drell-Yan measurements to probe sea quark dynamics and advance our understanding of nucleon structure.
We study the
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A position-sensitive Schottky Cavity Doublet (SCD) has been developed to improve the accuracy of isochronous mass measurement at the Rare Radio-Isotope Ring (R3) at RIBF-RIKEN, Japan. The aim is to increase the accuracy of the position measurement which is used to correct the momentum spread, thus reducing the uncertainty in the mass determination. The detector consists of a cylindrical reference cavity and an elliptical position-sensitive cavity which uses an offset beam-pipe to make a relation between the Schottky power and the horizontal position. The uncertainty in the power response can be improved by minimising free parameters inside the power equation, providing a second-order correction for the position determination. This requires a large dispersion and momentum spread to effectively characterise the SCD acceptance, which simulations show is achieved when using 76Zn as a reference isotope. A key parameter to minimise is the uncertainty of the impedance map which relates power to position in the elliptical cavity. We find that an uncertainty in impedance of 0.3 Ω results in a precision equal to that of the current mass measurement method. Additionally, measuring momentum with the SCD enables the removal of other detectors from the beam-line which drastically reduce the yield of high Z beams via charge-change interactions.
A position-sensitive Schottky Cavity Doublet (SCD) has been developed to improve the accuracy of isochronous mass measurement at the Rare Radio-Isotope Ring (R3) at RIBF-RIKEN, Japan. The aim is to increase the accuracy of the position measurement which is used to correct the momentum spread, thus reducing the uncertainty in the mass determination. The detector consists of a cylindrical reference cavity and an elliptical position-sensitive cavity which uses an offset beam-pipe to make a relation between the Schottky power and the horizontal position. The uncertainty in the power response can be improved by minimising free parameters inside the power equation, providing a second-order correction for the position determination. This requires a large dispersion and momentum spread to effectively characterise the SCD acceptance, which simulations show is achieved when using 76Zn as a reference isotope. A key parameter to minimise is the uncertainty of the impedance map which relates power to position in the elliptical cavity. We find that an uncertainty in impedance of 0.3 Ω results in a precision equal to that of the current mass measurement method. Additionally, measuring momentum with the SCD enables the removal of other detectors from the beam-line which drastically reduce the yield of high Z beams via charge-change interactions.
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We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment,\begin{document}$ a_{\mu} $\end{document} ![]()
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. Utilizing a coupled non-perturbative framework combining Schwinger-Dyson and Bethe-Salpeter equations, we first compute the mass and weak decay constant of the pion's first radial excitation. Initial results are provided for the Rainbow-Ladder (RL) approximation, followed by an extended beyond RL (BRL) analysis that incorporates meson cloud effects. Building on our previous work, this analysis demonstrates that an accurate description of the first radial excitation can be achieved without the need for a reparametrization of the interaction kernels. Having demonstrated the effectiveness of the truncation scheme, we proceed to calculate the corresponding EFF, from which we derive the contribution of the pion's first radial excitation to the HLbL component of the muon's anomalous magnetic moment, producing \begin{document}$ a_{\mu}^{\pi_1-\text{box}}(\text{RL}) = -(2.03 \pm 0.12) \times 10 ^{-13} $\end{document} ![]()
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, \begin{document}$ a_{\mu}^{\pi_1-\text{box}}(\text{BRL}) = $\end{document} ![]()
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\begin{document}$ -(2.02 \pm 0.10) \times 10 ^{-13} $\end{document} ![]()
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. Our computation also sets the groundwork for calculating related pole contributions of excited pseudoscalar mesons to \begin{document}$ a_{\mu} $\end{document} ![]()
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.
We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment,
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An invariant-mass spectroscopy has been performed to search for possible resonance states in the loosely-bound neutron-rich 15C nucleus. By detecting alpha and 11Be in coincidence, the excitation energy spectrum for 15C is reconstructed. To estimate physical background from non-resonant prompt alpha particles, a recently proposed weighted event-mixing method with phenomenological reduced weighting at around the alpha-decay threshold is employed to account for the depletion in the prompt alpha's contribution due likely to the Coulomb final-state interactions. A new weighted mixed-event method that focuses on a robust treatment of the Coulomb effect is also proposed. Fitting the spectrum using the background estimated with these two methods, up to two resonance state candidates are proposed. A further experiment with improved statistics and theoretical calculations are called for to confirm these resonance states.
An invariant-mass spectroscopy has been performed to search for possible resonance states in the loosely-bound neutron-rich 15C nucleus. By detecting alpha and 11Be in coincidence, the excitation energy spectrum for 15C is reconstructed. To estimate physical background from non-resonant prompt alpha particles, a recently proposed weighted event-mixing method with phenomenological reduced weighting at around the alpha-decay threshold is employed to account for the depletion in the prompt alpha's contribution due likely to the Coulomb final-state interactions. A new weighted mixed-event method that focuses on a robust treatment of the Coulomb effect is also proposed. Fitting the spectrum using the background estimated with these two methods, up to two resonance state candidates are proposed. A further experiment with improved statistics and theoretical calculations are called for to confirm these resonance states.
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In this paper, a feedforward neural network (FNN) approach is employed to optimize three local mass models (GK, GKs, and GK+J). It is found that adding physical quantities related to pairing effect in the input layer can effectively improve the prediction accuracy of local models. For the known masses in AME2012, the FNN reduces the root-mean-square deviation between theory and experiment for the three mass models by 11 keV, 32 keV and 623 keV. Among them, the improvement effect of light mass region with mass number between 16 and 60 is better than that of medium and heavy mass regions. It also has good optimization results when extrapolating AME2012 to AME2020 and the latest measured masses after AME2020. Based on the improved mass data, the separation energies for single- and two-proton (neutron) emissions, and α-decay energies are obtained, which agree well with the experiment.
In this paper, a feedforward neural network (FNN) approach is employed to optimize three local mass models (GK, GKs, and GK+J). It is found that adding physical quantities related to pairing effect in the input layer can effectively improve the prediction accuracy of local models. For the known masses in AME2012, the FNN reduces the root-mean-square deviation between theory and experiment for the three mass models by 11 keV, 32 keV and 623 keV. Among them, the improvement effect of light mass region with mass number between 16 and 60 is better than that of medium and heavy mass regions. It also has good optimization results when extrapolating AME2012 to AME2020 and the latest measured masses after AME2020. Based on the improved mass data, the separation energies for single- and two-proton (neutron) emissions, and α-decay energies are obtained, which agree well with the experiment.
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Our previous study [A. H. Al-Ghamdi et al, JTUSCI 16 (2022) 1026] provided a comprehensive analysis of elastic scattering angular distributions (ADs) for the 7Li + 28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal or breakup, by examining the energy dependence of volume integrals across various interaction potentials. The current study extends this work by investigating the effects of 7Li breakup into a valence particle (triton) orbiting a core (alpha) in the context of a 28Si target, as well as the influence of the 28Si(7Li,α)31P triton transfer reaction on the elastic ADs of the 7Li + 28Si system. The results demonstrate the significance of coupling to the 7Li breakup channel and its subsequent impact on the elastic scattering channel. This strong coupling generates a dynamic polarization potential (DPP), leading to a reduction in potential strengths. A semi-microscopic DPP approach was utilized to model this effect, employing the continuum discretized coupled channels (CDCC) method. An effective potential (Ueff), considered as the sum of cluster folding and dynamic polarization potentials, the later was generated using the trivially equivalent local potential (TELP) approach, was employed successfully to reproduce the 7Li + 28Si ADs data. Furthermore, the analysis was broadened to assess the effect of the triton stripping reaction 28Si(7Li,α)31P on the elastic 7Li + 28Si scattering.
Our previous study [A. H. Al-Ghamdi et al, JTUSCI 16 (2022) 1026] provided a comprehensive analysis of elastic scattering angular distributions (ADs) for the 7Li + 28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal or breakup, by examining the energy dependence of volume integrals across various interaction potentials. The current study extends this work by investigating the effects of 7Li breakup into a valence particle (triton) orbiting a core (alpha) in the context of a 28Si target, as well as the influence of the 28Si(7Li,α)31P triton transfer reaction on the elastic ADs of the 7Li + 28Si system. The results demonstrate the significance of coupling to the 7Li breakup channel and its subsequent impact on the elastic scattering channel. This strong coupling generates a dynamic polarization potential (DPP), leading to a reduction in potential strengths. A semi-microscopic DPP approach was utilized to model this effect, employing the continuum discretized coupled channels (CDCC) method. An effective potential (Ueff), considered as the sum of cluster folding and dynamic polarization potentials, the later was generated using the trivially equivalent local potential (TELP) approach, was employed successfully to reproduce the 7Li + 28Si ADs data. Furthermore, the analysis was broadened to assess the effect of the triton stripping reaction 28Si(7Li,α)31P on the elastic 7Li + 28Si scattering.
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We calculate the exact values of the quasinormal frequencies for massless perturbations with spin\begin{document}$ s\leq2 $\end{document} ![]()
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moving in pure accelerating spacetime. We use two different methods to transfer the perturbation equations into the form of hypergeometric differential equations and obtain the same quasinormal frequencies. These purely imaginary spectra are shown to be independent of the spin of the perturbation and match those of the so-called acceleration modes of accelerating black holes after taking the Minkowski limit. This implies that the acceleration modes actually originate from the pure accelerating spacetime and the appearance of black holes would deform the spectra. In addition, we calculate the quasinormal frequencies of scalar, electromagnetic and gravitational perturbations of D-dimensional de Sitter spacetime and compare them with previous results to verify the validity of our method.
We calculate the exact values of the quasinormal frequencies for massless perturbations with spin
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The rare radioactive-isotope (RI) ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs. Since the successful commissioning experiment in 2015, the time of flight mass measurement technique has been established through the test experiments using unstable nuclei with well-known masses. The experiments for unknown masses were started in 2018. While conducting the experiments, we continue to develop equipment to further improve the efficiency and precision for mass measurements. The upgraded kicker system can make a magnetic field with an extractable duration equivalent to revolution time of the ring. It is essential for extracting extremely rare events as well as shortening the measurement time compared with the initial experiments. New steering magnets make it possible to eliminate uncertain vertical beam deviation that occurres upstream. As a result, we confirmed that the extraction yield was increased. A new resonant Schottky pick-up is able to detect single particles in timeframes on the order of milliseconds. It will be useful not only for beam diagnostics, but also for lifetime measurement experiments of extremely short-lived rare RIs planned as a future application.
The rare radioactive-isotope (RI) ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs. Since the successful commissioning experiment in 2015, the time of flight mass measurement technique has been established through the test experiments using unstable nuclei with well-known masses. The experiments for unknown masses were started in 2018. While conducting the experiments, we continue to develop equipment to further improve the efficiency and precision for mass measurements. The upgraded kicker system can make a magnetic field with an extractable duration equivalent to revolution time of the ring. It is essential for extracting extremely rare events as well as shortening the measurement time compared with the initial experiments. New steering magnets make it possible to eliminate uncertain vertical beam deviation that occurres upstream. As a result, we confirmed that the extraction yield was increased. A new resonant Schottky pick-up is able to detect single particles in timeframes on the order of milliseconds. It will be useful not only for beam diagnostics, but also for lifetime measurement experiments of extremely short-lived rare RIs planned as a future application.
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We propose a search strategy at the HL-LHC for a new neutral particle X that couples to W-bosons, using the process\begin{document}$ p p \to W^{\pm} X (\to W^{+} W^{-}) $\end{document} ![]()
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with a tri-W-boson final state. Focusing on events with two same-sign leptonic W-boson decays into muons and a hadronically decaying W-boson, our method leverages the enhanced signal-to-background discrimination achieved through a machine-learning-based multivariate analysis. Using the heavy photophobic axion-like particle (ALP) as a benchmark, we evaluate the discovery sensitivities on both production cross section times branching ratio \begin{document}$ \sigma(p p \to W^{\pm} X) \times \text{Br}(X \to W^{+} W^{-}) $\end{document} ![]()
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and the coupling \begin{document}$ g_{aWW} $\end{document} ![]()
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for the particle mass over a wide range of 170–3000 GeV at the HL-LHC with center-of-mass energy \begin{document}$ \sqrt{s} = 14 \, \text{ TeV} $\end{document} ![]()
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and integrated luminosity \begin{document}$ {\cal{L}} = 3 \, \text{ab}^{-1} $\end{document} ![]()
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. Our results show significant improvements in discovery sensitivity, particularly for masses above 300 GeV, compared to existing limits derived from CMS analyses of Standard Model (SM) tri-W-boson production at \begin{document}$ \sqrt{s} = 13 \, \text{ TeV} $\end{document} ![]()
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. This study demonstrates the potential of advanced selection techniques in probing the coupling of new particles to W-bosons and highlights the HL-LHC's capability to explore the physics beyond the SM.
We propose a search strategy at the HL-LHC for a new neutral particle X that couples to W-bosons, using the process
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The\begin{document}$ \gamma p \to \pi^0 \eta p $\end{document} ![]()
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reaction has been investigated by the CBELSA/TAPS Collaboration, revealing a narrow structure in the \begin{document}$ \eta p $\end{document} ![]()
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invariant mass distributions at a mass of 1700 MeV. In this study, we explore the possibility that the narrow structure is caused by a decay cascade via an intermediate nucleon resonance decaying to \begin{document}$ \eta p $\end{document} ![]()
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final states. The candidates for the intermediate nucleon resonances are \begin{document}$ N(1700)3/2^{-} $\end{document} ![]()
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and \begin{document}$ N(1710)1/2^{+} $\end{document} ![]()
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, with masses near the observed structure. We consider the t-channel ρ- and ω-exchange diagrams, the u-channel nucleon-pole exchange diagram, the contact term, and the s-channel pole diagrams of nucleon, Δ, and nucleon resonances when constructing the reaction amplitudes to reproduce the stripped individual contribution of the narrow structure. Our analysis indicates that the signature strength of the decay cascade \begin{document}$ \gamma p \to \pi^{0}N(1700)3/2^{-} \to \pi^{0}\eta p $\end{document} ![]()
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is too weak to reach the experimental curve of the narrow structure due to the small decay branching ratio of \begin{document}$ N(1700)3/2^{-} $\end{document} ![]()
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to \begin{document}$ \eta p $\end{document} ![]()
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. Although the decay cascade \begin{document}$ \gamma p \to \pi^{0}N(1710)1/2^{+} \to \pi^{0}\eta p $\end{document} ![]()
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can qualitatively reproduce the experimental curve of the invariant mass distributions, its cross-section width is much larger than that of the corresponding experimental curve. Therefore, we conclude that the decay cascade via an intermediate nucleon resonance could not be the reason leading to the narrow structure in the \begin{document}$ \eta p $\end{document} ![]()
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invariant mass distributions of the \begin{document}$ \gamma p \to \pi^0 \eta p $\end{document} ![]()
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reaction.
The
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, doi: 10.1088/1674-1137/adcf10
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We analyzed quasifission lifetimes of superheavy elements (SHEs) within\begin{document}$ 104\le Z\le 120 $\end{document} ![]()
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and mass number range \begin{document}$ 243\le A\le 301 $\end{document} ![]()
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considering various projectile-target combinations. Nucleus-nucleus potentials were evaluated using the nuclear proximity 2010 model, and quasifission barriers were evaluated as the difference between minimum and maximum potentials. The quasifission lifetimes varied from 0.1 zs to 2040 zs, with lifetimes above 1600 zs for \begin{document}$ ^{249}_{145} $\end{document} ![]()
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Rf, \begin{document}$ ^{248}_{143} $\end{document} ![]()
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Db, \begin{document}$ ^{260}_{154} $\end{document} ![]()
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Sg, and \begin{document}$ ^{263}_{156} $\end{document} ![]()
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Hs. The quasifission lifetimes decreased with increasing Z, dropping to 0.1 zs at Z=120. Shorter quasifission lifetimes may contribute to the reduction in production cross-sections from nanobarns to picobarns for elements with Z=104 to Z=118. Furthermore, the impact of angular momentum on quasifission barriers exhibits a decreasing trend as the atomic number increases. The shortest lifetime of 253 zs is observed at Z= 120 while longer lifetimes, such as 659 zs for 64Ni+196Pt, suggest enhanced stability. The model was validated against data available in literature, generally producing lower values except for 34S+186W, and 238U+48Ca, where significant increases were observed.
We analyzed quasifission lifetimes of superheavy elements (SHEs) within
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In this study, we present several improvements of the non-relativistic Friedrichs-Lee model with multiple discrete and continuous states and still retain its solvability. Our findings establish a solid theoretical basis for the exploration of resonance phenomena in scenarios involving multiple interfering states across various channels. The scattering amplitudes associated with the continuum states naturally adhere to coupled-channel unitarity, rendering this framework particularly valuable for investigating hadronic resonant states appearing in multiple coupled channels. Moreover, this generalized framework exhibits a wide-range applicability, enabling investigations into resonance phenomena across diverse physical domains, including hadron physics, nuclear physics, optics, and cold atom physics, among others.
In this study, we present several improvements of the non-relativistic Friedrichs-Lee model with multiple discrete and continuous states and still retain its solvability. Our findings establish a solid theoretical basis for the exploration of resonance phenomena in scenarios involving multiple interfering states across various channels. The scattering amplitudes associated with the continuum states naturally adhere to coupled-channel unitarity, rendering this framework particularly valuable for investigating hadronic resonant states appearing in multiple coupled channels. Moreover, this generalized framework exhibits a wide-range applicability, enabling investigations into resonance phenomena across diverse physical domains, including hadron physics, nuclear physics, optics, and cold atom physics, among others.
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Recent high-resolution observations have established a strong link between black hole jets and accretion disk structures, particularly in the 3.5 mm wavelength band [Nature. 616,686 (2023)]. In this work, we propose a "jet-modified Novikov-Thorne disk model" that explicitly incorporates jet luminosity into the accretion disk radiation framework. By integrating synchrotron radiation from relativistic electrons in the jet, we derive a modified luminosity function that accounts for both the accretion disk and jet contributions. Our analysis demonstrates that the inclusion of jet luminosity enhances the total accretion disk luminosity by approximately 33.5%, as derived from the integration of radiative flux. Furthermore, we compare our modified model with the standard Novikov-Thorne model and find that the jet contribution remains significant across different observational inclinations. These results highlight the necessity of incorporating jet effects when estimating the observable flux of black hole accretion systems, which has direct implications for future astronomical observations.
Recent high-resolution observations have established a strong link between black hole jets and accretion disk structures, particularly in the 3.5 mm wavelength band [Nature. 616,686 (2023)]. In this work, we propose a "jet-modified Novikov-Thorne disk model" that explicitly incorporates jet luminosity into the accretion disk radiation framework. By integrating synchrotron radiation from relativistic electrons in the jet, we derive a modified luminosity function that accounts for both the accretion disk and jet contributions. Our analysis demonstrates that the inclusion of jet luminosity enhances the total accretion disk luminosity by approximately 33.5%, as derived from the integration of radiative flux. Furthermore, we compare our modified model with the standard Novikov-Thorne model and find that the jet contribution remains significant across different observational inclinations. These results highlight the necessity of incorporating jet effects when estimating the observable flux of black hole accretion systems, which has direct implications for future astronomical observations.
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In this study, neutron activation experiments were performed to measure the (n,2n) reaction cross section for 80Kr at five neutron energies: 13.59±0.12, 13.86±0.15, 14.13±0.16, 14.70±0.13, and 14.94±0.02 MeV, using a highly enriched gaseous sample. The neutron energies and their uncertainties were determined using the Q-value equation for the 3H(d,n)4He reaction, accounting for the solid angle of the sample. The 93Nb(n,2n)92mNb reaction was employed to monitor the neutron flux. Eight characteristic gamma rays of the produced nucleus were selected to determine the activity of the generated nuclei. The final cross sections were obtained using a weighted average method. The self-absorption and cascade of rays as well as the geometry and solid angles of the sample were corrected. The 80Kr(n,2n)79Kr reaction cross sections obtained in this work exhibited the smallest uncertainty compared to the existing literature, which provided improved experimental constraints for the prediction of excitation curves, thereby enhancing the quality of the corresponding database. The measured results were compared with previously reported experimental values, empirical and systematic formula predictions, theoretical calculations from TALYS-1.96 with six adjustable energy level densities, and evaluated database results. Our experimental results demonstrated high precision and extended the energy range appropriately, offering valuable insights for future studies.
In this study, neutron activation experiments were performed to measure the (n,2n) reaction cross section for 80Kr at five neutron energies: 13.59±0.12, 13.86±0.15, 14.13±0.16, 14.70±0.13, and 14.94±0.02 MeV, using a highly enriched gaseous sample. The neutron energies and their uncertainties were determined using the Q-value equation for the 3H(d,n)4He reaction, accounting for the solid angle of the sample. The 93Nb(n,2n)92mNb reaction was employed to monitor the neutron flux. Eight characteristic gamma rays of the produced nucleus were selected to determine the activity of the generated nuclei. The final cross sections were obtained using a weighted average method. The self-absorption and cascade of rays as well as the geometry and solid angles of the sample were corrected. The 80Kr(n,2n)79Kr reaction cross sections obtained in this work exhibited the smallest uncertainty compared to the existing literature, which provided improved experimental constraints for the prediction of excitation curves, thereby enhancing the quality of the corresponding database. The measured results were compared with previously reported experimental values, empirical and systematic formula predictions, theoretical calculations from TALYS-1.96 with six adjustable energy level densities, and evaluated database results. Our experimental results demonstrated high precision and extended the energy range appropriately, offering valuable insights for future studies.
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The spin alignment of\begin{document}$ J/\psi $\end{document} ![]()
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with respect to event plane in relativistic heavy ion collisions exhibits a significant signal. We propose a possible mechanism for spin alignment through spin dependent dissociation of quarkonia in a vortical quark-gluon plasma. The spin dependent dissociation is realized through inelastic scattering between constituents of quarkonium and those of quark-gluon plasma polarized by the vorticity. The spin dependent dissociation rate is found to depend on the directions of vorticity, quantization axis, and quark momentum. We implement our results in a dissociation dominated evolution model for quarkonia in the Bjorken flow, finding the spin 0 state is slightly suppressed compared to the average of the other two, which is consistent with the sign found in experiments. We also find absence of logarithmic enhancement in binding energy in the vortical correction to dissociation rate, which is understood from the requirement that a spin dependent dissociation can only come from quark coupling to a pair of chromomagnetic and chromoelectric field.
The spin alignment of
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We investigate the entanglement harvesting protocol within the context of cylindrical gravitational waves given first by Einstein and Rosen, focusing on the interactions between non-relativistic quantum systems and linearized quantum gravity. We study how two spatially separated detectors can extract entanglement from the specific spacetime in the presence of gravitational waves, which provides a precise quantification of the entanglement that can be harvested using these detectors. In particular, we obtain the relation between harvested entanglement and the distance to wave sources that emits gravitational waves and analyze the detectability using quantum Fisher information. The enhanced detectability demonstrates the advantages of cylindrical symmetric gravitational waves.
We investigate the entanglement harvesting protocol within the context of cylindrical gravitational waves given first by Einstein and Rosen, focusing on the interactions between non-relativistic quantum systems and linearized quantum gravity. We study how two spatially separated detectors can extract entanglement from the specific spacetime in the presence of gravitational waves, which provides a precise quantification of the entanglement that can be harvested using these detectors. In particular, we obtain the relation between harvested entanglement and the distance to wave sources that emits gravitational waves and analyze the detectability using quantum Fisher information. The enhanced detectability demonstrates the advantages of cylindrical symmetric gravitational waves.
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Non-destructive Schottky detectors are indispensable devices widely used in experiments at heavy-ion storage rings. In particular, they can be used to accurately determine the masses and lifetimes of short-lived exotic nuclear species. Single-ion sensitivity – which enables highest sensitivity – has been regularly achieved in the past utilizing resonant cavity detectors. Recent designs and analysis methods aim at pushing the limits of measurement accuracy by increasing the dimensionality of the acquired data, namely the position of the particle as well as the phase difference between several detectors. This work describes current methods and future perspectives of Schottky detection techniques focusing at their application for mass and lifetime measurements of the most rare and simultaneously short-lived radio nuclides.
Non-destructive Schottky detectors are indispensable devices widely used in experiments at heavy-ion storage rings. In particular, they can be used to accurately determine the masses and lifetimes of short-lived exotic nuclear species. Single-ion sensitivity – which enables highest sensitivity – has been regularly achieved in the past utilizing resonant cavity detectors. Recent designs and analysis methods aim at pushing the limits of measurement accuracy by increasing the dimensionality of the acquired data, namely the position of the particle as well as the phase difference between several detectors. This work describes current methods and future perspectives of Schottky detection techniques focusing at their application for mass and lifetime measurements of the most rare and simultaneously short-lived radio nuclides.
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We analyze the recent data from the BESIII collaboration on the\begin{document}$ X(3872) $\end{document} ![]()
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state in the \begin{document}$ J/\psi\pi^+\pi^- $\end{document} ![]()
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and \begin{document}$ D^0\bar{D}^0\pi^0 $\end{document} ![]()
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decay channels. The quantum number and mass of the \begin{document}$ X(3872) $\end{document} ![]()
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state allow us to exploit the universal feature of the very near-threshold \begin{document}$ D\bar D^* $\end{document} ![]()
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scattering in the S wave. The analysis of \begin{document}$ J/\psi\pi^+\pi^- $\end{document} ![]()
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data and \begin{document}$ D^0\bar{D}^0\pi^0 $\end{document} ![]()
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data separately as well as the combined analysis of these data together, all support the conclusion that \begin{document}$ X(3872) $\end{document} ![]()
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is an extremely weakly bound charm meson molecule.
We analyze the recent data from the BESIII collaboration on the
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This paper investigates the neutrino transition magnetic moment in the\begin{document}$ U(1)_X $\end{document} ![]()
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SSM. \begin{document}$ U(1)_X $\end{document} ![]()
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SSM is the \begin{document}$ U(1) $\end{document} ![]()
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extension of Minimal Supersymmetric Standard Model (MSSM) and its local gauge group is extended to \begin{document}$ SU(3)_C\times SU(2)_L \times U(1)_Y\times U(1)_X $\end{document} ![]()
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. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to the MSSM, which can explain the results of neutrino oscillation experiments. The neutrino transition magnetic moment is induced by electroweak radiative corrections. By applying effective Lagrangian method and on-shell scheme, we study the associated Feynman diagrams and the transition magnetic moment of neutrinos in the model. We fit experimental data for neutrino mass variances and mixing angles. Based on the range of data selection, the influences of different sensitive parameters on the results are analysed. The numerical analysis shows that many parameters have an effect on the neutrino transition magnetic moment, such as \begin{document}$ g_X $\end{document} ![]()
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, \begin{document}$ M_2 $\end{document} ![]()
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, \begin{document}$ \mu $\end{document} ![]()
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, \begin{document}$ \lambda_H $\end{document} ![]()
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and \begin{document}$ g_{YX} $\end{document} ![]()
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. For our numerical results, the order of magnitude of \begin{document}$ \mu_{ij}^M/\mu_B $\end{document} ![]()
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is around \begin{document}$ 10^{-20} $\end{document} ![]()
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\begin{document}$ \sim $\end{document} ![]()
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\begin{document}$ 10^{-19} $\end{document} ![]()
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.
This paper investigates the neutrino transition magnetic moment in the
Published:
, doi: 10.1088/1674-1137/adc4cb
Abstract:
A method for the treatment of the neutron-proton (np) isovector pairing correlations at finite temperature is developed within the path integral formalism. It generalizes the recently proposed model using a similar approach in the pairing between like-particles case. The pairing terms in the total Hamiltonian are written in a square form in order to facilitate the use of the Hubbard-Stratonovitch transformation. The expression for the partition function of the system is then established. The gap equations, as well as the expressions for the energy, the entropy and the heat capacity of the system are deduced. As a first step, the formalism is numerically applied to the schematic Richardson model. As a second step, the method is applied to nuclei such as\begin{document}$ N=Z $\end{document} ![]()
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using the single-particle energies of a deformed Woods-Saxon mean-field. The variations in the gap parameters, the excitation energy and the heat capacity are studied as functions of the temperature. It is shown that the overall behavior of these quantities is similar to their homologues in the standard FTBCS model. We note in particular the existence of critical temperatures beyond which the pairing vanish. Moreover, it appears that in the framework of the present approach, the pairing effects persist beyond the critical temperatures predicted by the FTBCS model in the pairing between like-particles case or its generalization in the np pairing case.
A method for the treatment of the neutron-proton (np) isovector pairing correlations at finite temperature is developed within the path integral formalism. It generalizes the recently proposed model using a similar approach in the pairing between like-particles case. The pairing terms in the total Hamiltonian are written in a square form in order to facilitate the use of the Hubbard-Stratonovitch transformation. The expression for the partition function of the system is then established. The gap equations, as well as the expressions for the energy, the entropy and the heat capacity of the system are deduced. As a first step, the formalism is numerically applied to the schematic Richardson model. As a second step, the method is applied to nuclei such as
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We investigate the soft behavior of the tree-level Rutherford scattering processes mediated via t-channel one-graviton exchange. We consider two types of Rutherford scattering processes, e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in\begin{document}$ 1/M $\end{document} ![]()
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expansion, yet differ at the next-to-next-to-leading order, though some terms at this order still remain universal or depend on the target spin in a definite manner. The unpolarized cross sections in the second type are universal at the lowest order in projectile velocity expansion and through all orders in \begin{document}$ 1/M $\end{document} ![]()
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, independent of the spins of both projectile and target. The universality partially breaks down at relative order-\begin{document}$ v^2/M^2 $\end{document} ![]()
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, albeit some terms at this order still depend on the target spin in a specific manner.
We investigate the soft behavior of the tree-level Rutherford scattering processes mediated via t-channel one-graviton exchange. We consider two types of Rutherford scattering processes, e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in
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We investigate the bound-state equations in two-dimensional QCD in the\begin{document}$ N_c\to \infty $\end{document} ![]()
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limit. We consider two types of hadrons, an exotic "meson" (which is composed of a bosonic quark and a bosonic anti-quark), and an exotic "baryon" (composed of a fermionic quark and a bosonic antiquark). Using the Hamiltonian operator approach, we derive the corresponding bound-state equations for both types of hadrons from the perspectives of the light-front quantization and equal-time quantization, and confirm the known results. We also present a novel diagrammatic derivation for the exotic "meson" bound-state equation in the equal-time quantization. The bound-state equation for the exotic baryons in the equal-time quantization in two-dimensional QCD is new. We also numerically solve various bound-state equations, obtain the hadron spectrum and the bound-state wave functions of the lowest-lying states. We explicitly demonstrate the pattern that as the hadron is boosted to the infinite-momentum frame, the forward-moving bound-state wave function approaches the corresponding light-front wave function.
We investigate the bound-state equations in two-dimensional QCD in the
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A future\begin{document}$ e^+e^- $\end{document} ![]()
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collider could run at the Z-pole to perform important electroweak (EW) precision measurements, while such a run may not be viable for a future muon collider. This however can be compensated by the measurements of other EW processes, taking advantage of the high energy and large luminosity of the muon collider. In this paper, we consider the measurements of the vector boson fusion processes of \begin{document}$ WW/WZ/W\gamma $\end{document} ![]()
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to a pair of fermions (along with a \begin{document}$ \nu_{\mu}\bar{\nu}_{\mu} $\end{document} ![]()
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or \begin{document}$ \nu_{\mu}\mu^+/\bar{\nu}_{\mu}\mu^- $\end{document} ![]()
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pair) at a high-energy muon collider and study their potential in probing the EW observables. We consider two run scenarios for the muon collider with center-of-mass energy of 10 TeV and 30 TeV, respectively, and focus on the processes involving \begin{document}$ f=b,c,\tau $\end{document} ![]()
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and the dimension-6 operators that directly modify the corresponding fermions coupling to the \begin{document}$ Z/W $\end{document} ![]()
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bosons. The invariant mass distribution of the \begin{document}$ f\bar{f} $\end{document} ![]()
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pair helps to separate the events from the \begin{document}$ Z/W $\end{document} ![]()
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resonance and the high-energy ones, while the polar angle of the outing fermion also provides additional information. By performing a chi-squared analysis on the binned distributions and combining the information from the WW and \begin{document}$ WZ/W\gamma $\end{document} ![]()
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fusion processes, all relevant Wilson coefficients can be constrained simultaneously. The precision surpasses the current EW measurement constraints and is even competitive with future \begin{document}$ e^+e^- $\end{document} ![]()
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colliders. Our analysis can be included in a more complete framework which is needed to fully determine the potential of muon colliders in EW precision measurements.
A future
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We study the flavor-changing bottom quark radiative decay\begin{document}$ b {\rightarrow} s \gamma $\end{document} ![]()
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induced at one-loop level within the minimal gauged two-Higgs-doublet model (G2HDM). Among the three new contributions to this rare process in G2HDM, we find that only the charged Higgs \begin{document}$ {\cal{H}}^\pm $\end{document} ![]()
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contribution can be constrained by the current global fit data in B-physics. Other two contributions from the complex vectorial dark matter \begin{document}$ {\cal{W}} $\end{document} ![]()
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and dark Higgs \begin{document}$ {\cal{D}} $\end{document} ![]()
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are not sensitive to the current data. Combining with theoretical constraints imposed on the scalar potential and electroweak precision data for the oblique parameters, we exclude mass regions \begin{document}$ m_{\cal{H}}^\pm \lesssim 250 $\end{document} ![]()
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GeV and \begin{document}$ m_{\cal{D}} \lesssim 100 $\end{document} ![]()
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GeV at the 95% confidence level.
We study the flavor-changing bottom quark radiative decay
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Elastic α-12C scattering for\begin{document}$ l=2 $\end{document} ![]()
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and E2 transition of radiative α capture on 12C, 12C(α,γ)16O, are studied in cluster effective field theory. Due to the problem in fixing the asymptotic normalization coefficient (ANC) of the subthreshold \begin{document}$ 2_1^+ $\end{document} ![]()
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state of 16O, equivalently, the effective range parameters of the \begin{document}$ 2_1^+ $\end{document} ![]()
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state, from the elastic scattering data, we introduce the conditions that lead to a large value of the ANC. In addition, d-wave phase shift data of the elastic scattering up to the α energy, \begin{document}$ E_\alpha=10 $\end{document} ![]()
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MeV, which contain resonant \begin{document}$ 2_4^+ $\end{document} ![]()
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state of 16O, are also introduced in the study. Applying the conditions, the parameters of the S matrix of the elastic scattering for \begin{document}$ l=2 $\end{document} ![]()
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are fitted to the phase shift data, and the fitted parameters are employed in the calculation of astrophysical \begin{document}$ S_{E2} $\end{document} ![]()
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factor of 12C(α,γ)16O; we extrapolate the \begin{document}$ S_{E2} $\end{document} ![]()
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factor to the Gamow-peak energy, \begin{document}$ E_G=0.3 $\end{document} ![]()
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MeV. We find that the conditions lead to significant effects in the observables of the \begin{document}$ 2_4^+ $\end{document} ![]()
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state of 16O and the estimate of the \begin{document}$ S_{E2} $\end{document} ![]()
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factor at \begin{document}$ E_G $\end{document} ![]()
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and confirm that the ANC of the \begin{document}$ 2_1^+ $\end{document} ![]()
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of 16O cannot be determined by the phase shift data for \begin{document}$ l=2 $\end{document} ![]()
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.
Elastic α-12C scattering for
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This study utilizes the PYTHIA8 Angantyr model to systematically investigate the effects of three nucleons correlation\begin{document}$C_{n^2p}$\end{document} ![]()
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on the light nuclei yield ratio \begin{document}$N_tN_p/N_d^2$\end{document} ![]()
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in Au+Au collisions at \begin{document}$\sqrt{s_{\mathrm{NN}}}$\end{document} ![]()
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= 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV. The analysis explores this property across different rapidity ranges, collision centralities, and collision energies, while also examining the roles of multi-parton interactions (MPI) and color reconnection (CR) mechanisms. The results show that the light nuclei yield ratio remains stable with changes in rapidity coverage and collision centrality but slightly increases with rising collision energy. The impact of CR on the light nuclei yield ratio depends entirely on the presence of MPI; when MPI is turned off, CR has no effect. Additionally, the three-nucleon correlation, enhances the light nuclei yield ratio in both central and peripheral collisions. However, the non-monotonic energy dependence observed in experiments, the peak at \begin{document}$\sqrt{s_{\mathrm{NN}}}=20\sim30$\end{document} ![]()
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GeV reported by the STAR experiment, cannot be explained by the Angantyr model due to its lack of key mechanisms related to the quark-gluon plasma (QGP). Nevertheless, the Angantyr model serves as an important baseline for studying collision behaviors in the absence of QGP effects.
This study utilizes the PYTHIA8 Angantyr model to systematically investigate the effects of three nucleons correlation
Published:
, doi: 10.1088/1674-1137/ad8ec2
Abstract:
The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a method to generate a significant phase difference through the interference between ρ and ω mesons, taking into account the G-parity allowed decay process of\begin{document}$\omega \rightarrow \pi^{+}\pi^{-}\pi^{0}$\end{document} ![]()
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and the G-parity-suppressed decay process of \begin{document}$\rho^{0} \rightarrow \pi^{+}\pi^{-}\pi^{0}$\end{document} ![]()
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in B meson decays. This interference can lead to notable changes in the CP asymmetry within the interference region. Additionally, we calculate the integral results for different phase space regions of the four-body decay process. We hope that our work provides valuable theoretical guidance for future experimental investigations on CP asymmetry in these decays.
The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a method to generate a significant phase difference through the interference between ρ and ω mesons, taking into account the G-parity allowed decay process of
Published:
Abstract:
Axion-like particles (ALPs) produced via the Primakoff process in the cores of Galactic core-collapse supernovae (SNe) could convert into MeV-energy γ-rays through interactions with the Milky Way’s magnetic field. To evaluate the detection prospects for such signals, we perform sensitivity projections for next-generation MeV telescopes by combining hypothetical instrument responses with realistic background estimates. Our analysis incorporates detailed simulations of the expected ALP flux from nearby SNe, the energy-dependent conversion probability in Galactic magnetic fields, and the telescope’s angular/energy resolution based on advanced detector designs. Background components are modeled using data from current MeV missions and extrapolated to future sensitivity regimes. Our simulations demonstrate that next-generation telescopes with improved effective areas and energy resolution could achieve sensitivity to photon-ALP couplings as low as\begin{document}$ g_{a\gamma} \approx 1.61 \times 10^{-13}\; \mathrm{GeV}^{-1} $\end{document} ![]()
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for ALP masses \begin{document}$ m_a \lesssim 10^{-9}\; \mathrm{eV} $\end{document} ![]()
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in Galactic Center. These results indicate that future MeV missions will probe unexplored regions of ALP parameter space, with conservative estimates suggesting they could constrain \begin{document}$ g_{a\gamma} $\end{document} ![]()
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values two orders of magnitude below current astrophysical limits. Such observations would provide the most stringent tests to date for axion-like particles as a dark matter candidate in the ultra-light mass regime.
Axion-like particles (ALPs) produced via the Primakoff process in the cores of Galactic core-collapse supernovae (SNe) could convert into MeV-energy γ-rays through interactions with the Milky Way’s magnetic field. To evaluate the detection prospects for such signals, we perform sensitivity projections for next-generation MeV telescopes by combining hypothetical instrument responses with realistic background estimates. Our analysis incorporates detailed simulations of the expected ALP flux from nearby SNe, the energy-dependent conversion probability in Galactic magnetic fields, and the telescope’s angular/energy resolution based on advanced detector designs. Background components are modeled using data from current MeV missions and extrapolated to future sensitivity regimes. Our simulations demonstrate that next-generation telescopes with improved effective areas and energy resolution could achieve sensitivity to photon-ALP couplings as low as
ISSN 1674-1137 CN 11-5641/O4
Original research articles, Ietters and reviews Covering theory and experiments in the fieids of
- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology
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