2025 Vol. 49, No. 8
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2025, 49(8): 083001. doi: 10.1088/1674-1137/adcdf3
Abstract:
Using 20.3 fb–1 of\begin{document}$e^+e^-$\end{document} ![]()
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\begin{document}$D^+\to\gamma e^+\nu_e$\end{document} ![]()
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\begin{document}$E_\gamma>10 $\end{document} ![]()
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\begin{document}$1.2\times10^{-5}$\end{document} ![]()
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Using 20.3 fb–1 of
2025, 49(8): 083101. doi: 10.1088/1674-1137/add5c7
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We study\begin{document}$ \cos2\phi $\end{document} ![]()
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\begin{document}$ h_{1L}^{\perp} $\end{document} ![]()
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\begin{document}$ h_{1L}^{\perp} $\end{document} ![]()
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\begin{document}$ A_{LL}^{\cos2\phi} $\end{document} ![]()
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We study
2025, 49(8): 083102. doi: 10.1088/1674-1137/adcd4b
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In this study, we present several improvements of the non-relativistic Friedrichs-Lee model with multiple discrete and continuous states while retaining 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, cold atom physics, etc.
In this study, we present several improvements of the non-relativistic Friedrichs-Lee model with multiple discrete and continuous states while retaining 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, cold atom physics, etc.
2025, 49(8): 083103. doi: 10.1088/1674-1137/add5c6
Abstract:
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 leads to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are often called sterile neutrinos. Applying the chiral perturbation theory, we calculate the transition amplitudes for light and heavy sterile neutrinos up to\begin{document}$ \mathcal{O}(Q^2/\Lambda^2_\chi) $\end{document} ![]()
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\begin{document}$ \Lambda_\chi $\end{document} ![]()
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We investigate the process of lepton-number-violating pion decay, which dominates the nuclear neutrinoless double beta decay induced by the short-range operator within the type-I seesaw mechanism. The type-I seesaw mechanism leads to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are often called sterile neutrinos. Applying the chiral perturbation theory, we calculate the transition amplitudes for light and heavy sterile neutrinos up to
2025, 49(8): 083104. doi: 10.1088/1674-1137/adc978
Abstract:
In this study, we investigated the neutrino transition magnetic moment in\begin{document}$ U(1)_X $\end{document} ![]()
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\begin{document}$ U(1)_X $\end{document} ![]()
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\begin{document}$ U(1) $\end{document} ![]()
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\begin{document}$S U(3)_C\times S U(2)_L \times U(1)_Y\times U(1)_X$\end{document} ![]()
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\begin{document}$ 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 $\end{document} ![]()
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\begin{document}$ g_{YX} $\end{document} ![]()
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\begin{document}$ \mu_{ij}^M/\mu_B $\end{document} ![]()
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\begin{document}$ 10^{-20} $\end{document} ![]()
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\begin{document}$ \sim $\end{document} ![]()
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\begin{document}$ 10^{-19} $\end{document} ![]()
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In this study, we investigated the neutrino transition magnetic moment in
2025, 49(8): 083105. doi: 10.1088/1674-1137/add674
Abstract:
Holographic models that consider classical vector fields in a 5-d background provide effective descriptions for heavy vector meson spectra. This is true both in vacuum and a thermal medium, such as quark gluon plasma. However, the manner in which these phenomenological models work is unclear. In particular, what is the role of the fifth dimension, and what is the relation between the holographic 5-d background and physical (4-d) heavy mesons? Hadrons, in contrast to leptons, are composite particles with some internal structure that depends on the energy at which they are observed. In this study, a static meson is represented by a heavy quark-antiquark pair with an interaction described by a Nambu Goto string existing in the same 5-d background that provides field solutions leading to masses and decay constants of charmonium states. The resulting interaction potential is linear for large distances, with a string tension consistent with the effective Cornell potential. Introducing temperature T in the background, it is found for the\begin{document}$J/\psi$\end{document} ![]()
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Holographic models that consider classical vector fields in a 5-d background provide effective descriptions for heavy vector meson spectra. This is true both in vacuum and a thermal medium, such as quark gluon plasma. However, the manner in which these phenomenological models work is unclear. In particular, what is the role of the fifth dimension, and what is the relation between the holographic 5-d background and physical (4-d) heavy mesons? Hadrons, in contrast to leptons, are composite particles with some internal structure that depends on the energy at which they are observed. In this study, a static meson is represented by a heavy quark-antiquark pair with an interaction described by a Nambu Goto string existing in the same 5-d background that provides field solutions leading to masses and decay constants of charmonium states. The resulting interaction potential is linear for large distances, with a string tension consistent with the effective Cornell potential. Introducing temperature T in the background, it is found for the
2025, 49(8): 083106. doi: 10.1088/1674-1137/add115
Abstract:
We propose a search strategy at the HL-LHC for a new neutral particle X that couples to W-bosons, using the process\begin{document}$ p p \to W^{\pm} X (\to W^{+} W^{-}) $\end{document} ![]()
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\begin{document}$ \sigma(p p \to W^{\pm} X) \times \text{Br}(X \to W^{+} W^{-}) $\end{document} ![]()
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\begin{document}$ g_{aWW} $\end{document} ![]()
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\begin{document}$ \sqrt{s} = 14 \, \text{ TeV} $\end{document} ![]()
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\begin{document}$ {\cal{L}} = 3 \, \text{ab}^{-1} $\end{document} ![]()
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\begin{document}$ \sqrt{s} = 13 \, \text{ TeV} $\end{document} ![]()
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We propose a search strategy at the HL-LHC for a new neutral particle X that couples to W-bosons, using the process
2025, 49(8): 083107. doi: 10.1088/1674-1137/add873
Abstract:
We study flavor-changing bottom quark radiative decay\begin{document}$ b {\rightarrow} s \gamma $\end{document} ![]()
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\begin{document}$ {\cal{H}}^\pm $\end{document} ![]()
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\begin{document}$ {\cal{W}} $\end{document} ![]()
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\begin{document}$ {\cal{D}} $\end{document} ![]()
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\begin{document}$ m_{\cal{H}}^\pm \lesssim 250 $\end{document} ![]()
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\begin{document}$ m_{\cal{D}} \lesssim 100 $\end{document} ![]()
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We study flavor-changing bottom quark radiative decay
2025, 49(8): 083108. doi: 10.1088/1674-1137/add259
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We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment,\begin{document}$ a_{\mu} $\end{document} ![]()
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\begin{document}$ 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} $\end{document} ![]()
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\begin{document}$ a_{\mu} $\end{document} ![]()
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We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment,
2025, 49(8): 083109. doi: 10.1088/1674-1137/add09f
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The\begin{document}$ \gamma p \to \pi^0 \eta p $\end{document} ![]()
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\begin{document}$ \eta p $\end{document} ![]()
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\begin{document}$ \eta p $\end{document} ![]()
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\begin{document}$ N(1700)3/2^{-} $\end{document} ![]()
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\begin{document}$ N(1710)1/2^{+} $\end{document} ![]()
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\begin{document}$ \gamma p \to \pi^{0}N(1700)3/2^{-} \to \pi^{0}\eta p $\end{document} ![]()
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\begin{document}$ N(1700)3/2^{-} $\end{document} ![]()
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\begin{document}$ \eta p $\end{document} ![]()
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\begin{document}$ \gamma p \to \pi^{0}N(1710)1/2^{+} \to \pi^{0}\eta p $\end{document} ![]()
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\begin{document}$ \eta p $\end{document} ![]()
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\begin{document}$ \gamma p \to \pi^0 \eta p $\end{document} ![]()
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The
2025, 49(8): 084001. doi: 10.1088/1674-1137/add10c
Abstract:
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, we reconstruct the excitation energy spectrum for 15C. To estimate the physical background from non-resonant prompt alpha particles, we employ a recently proposed weighted event-mixing method with phenomenological reduced weighting at around the alpha-decay threshold to account for the depletion in the prompt alpha's contribution owing 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. Through fitting the spectrum using the background estimated with these two methods, up to two resonance state candidates are proposed. Further experiments with improved statistics and theoretical calculations are called for to confirm these resonance states.
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, we reconstruct the excitation energy spectrum for 15C. To estimate the physical background from non-resonant prompt alpha particles, we employ a recently proposed weighted event-mixing method with phenomenological reduced weighting at around the alpha-decay threshold to account for the depletion in the prompt alpha's contribution owing 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. Through fitting the spectrum using the background estimated with these two methods, up to two resonance state candidates are proposed. Further experiments with improved statistics and theoretical calculations are called for to confirm these resonance states.
2025, 49(8): 084002. doi: 10.1088/1674-1137/add70e
Abstract:
As the LHC beams cannot be polarized, introducing a dense polarized gas target at the LHCb experiment at CERN, to be operated concurrently with beam-beam collisions, will facilitate fixed-target interactions to explore a new energy regime of spin physics measurements. Unfortunately, typical surface coatings used to avoid polarization losses, such as water, Teflon, or aluminum, are prohibited due to restrictions imposed by vacuum and beam policies. The former atomic beam source for the polarized target at ANKE@COSY (Forschungszentrum Jülich), an accompanying Lamb-shift polarimeter, and a storage cell chamber inside a superconducting magnet provide a perfect test stand to investigate the properties of a storage cell coated with amorphous carbon. A significant recombination rate, ranging from 93% to 100%, and preservation of polarization during recombination surpassing 74% were observed. We successfully produced\begin{document}$ \mathrm{H}_2 $\end{document} ![]()
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\begin{document}$ P\sim 0.59 $\end{document} ![]()
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\begin{document}$ \mathrm{H}_3^+ $\end{document} ![]()
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\begin{document}$ \mathrm{HD} $\end{document} ![]()
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As the LHC beams cannot be polarized, introducing a dense polarized gas target at the LHCb experiment at CERN, to be operated concurrently with beam-beam collisions, will facilitate fixed-target interactions to explore a new energy regime of spin physics measurements. Unfortunately, typical surface coatings used to avoid polarization losses, such as water, Teflon, or aluminum, are prohibited due to restrictions imposed by vacuum and beam policies. The former atomic beam source for the polarized target at ANKE@COSY (Forschungszentrum Jülich), an accompanying Lamb-shift polarimeter, and a storage cell chamber inside a superconducting magnet provide a perfect test stand to investigate the properties of a storage cell coated with amorphous carbon. A significant recombination rate, ranging from 93% to 100%, and preservation of polarization during recombination surpassing 74% were observed. We successfully produced
2025, 49(8): 084003. doi: 10.1088/1674-1137/add680
Abstract:
The origin of boron in the solar system has not yet been clearly understood. We studied the light mass nuclear reactions and neutrino-induced reactions that play important roles in the nucleosynthesis of A=11 nuclei in the core-collapse supernova (CCSN). We found that the production of A=11 nuclei, particularly 11C, is sensitive to the radioactive nuclear reaction 11C\begin{document}$ (\alpha,p)^{14} $\end{document} ![]()
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\begin{document}$ (\alpha,p)^{14} $\end{document} ![]()
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\begin{document}$ M_r=3.78-4.4M_{\odot} $\end{document} ![]()
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\begin{document}$ (\alpha,p)^{14} $\end{document} ![]()
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\begin{document}$ T=0.2-1 $\end{document} ![]()
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The origin of boron in the solar system has not yet been clearly understood. We studied the light mass nuclear reactions and neutrino-induced reactions that play important roles in the nucleosynthesis of A=11 nuclei in the core-collapse supernova (CCSN). We found that the production of A=11 nuclei, particularly 11C, is sensitive to the radioactive nuclear reaction 11C
2025, 49(8): 084004. doi: 10.1088/1674-1137/add70c
Abstract:
Delayed γ-ray spectroscopy of 185Au was studied at the Argonne Gas-Filled Analyzer. A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis, decaying via a 294.8(3) keV transition. Based on Weisskopf estimates, the multipolarity of the 295 keV transition is assigned to be E1, M1, E2, or M2. Possible configurations for this new isomer are discussed based on configuration-constrained potential energy surface calculations.
Delayed γ-ray spectroscopy of 185Au was studied at the Argonne Gas-Filled Analyzer. A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis, decaying via a 294.8(3) keV transition. Based on Weisskopf estimates, the multipolarity of the 295 keV transition is assigned to be E1, M1, E2, or M2. Possible configurations for this new isomer are discussed based on configuration-constrained potential energy surface calculations.
2025, 49(8): 084005. doi: 10.1088/1674-1137/adcc90
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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 than the values in 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 than the values in 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.
2025, 49(8): 084006. doi: 10.1088/1674-1137/add8fb
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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}{\rm Re}$\end{document} ![]()
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\begin{document}$^{165}{\rm{Ho}}$\end{document} ![]()
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\begin{document}$^{16}{\rm{O}}$\end{document} ![]()
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\begin{document}$^{177}{\rm{Re}}$\end{document} ![]()
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\begin{document}$\pi i_{13/2}[660]1/2^+$\end{document} ![]()
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\begin{document}$\pi d_{5/2}[402]5/2^+$\end{document} ![]()
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\begin{document}$\pi i_{13/2}$\end{document} ![]()
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\begin{document}$Q_t$\end{document} ![]()
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\begin{document}$\pi i_{13/2}$\end{document} ![]()
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\begin{document}$Q_t$\end{document} ![]()
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\begin{document}$\pi d_{5/2}$\end{document} ![]()
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\begin{document}$Q_t$\end{document} ![]()
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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
2025, 49(8): 084007. doi: 10.1088/1674-1137/adcc00
Abstract:
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 is the highest level of sensitivity – has been regularly achieved in the past by utilizing resonant cavity detectors. Recent designs and analysis methods aim to push 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 paper describes current methods and future perspectives for Schottky detection techniques, with a focus on their application to 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 is the highest level of sensitivity – has been regularly achieved in the past by utilizing resonant cavity detectors. Recent designs and analysis methods aim to push 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 paper describes current methods and future perspectives for Schottky detection techniques, with a focus on their application to mass and lifetime measurements of the most rare and simultaneously short-lived radio nuclides.
2025, 49(8): 084101. 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 for pairing between like-particles. The pairing terms in the total Hamiltonian are expressed in a square form 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, entropy, and heat capacity of the system are deduced. In a first step, the formalism is numerically applied to the schematic Richardson model. In a second step, the method is applied to nuclei with\begin{document}$ N=Z $\end{document} ![]()
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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 for pairing between like-particles. The pairing terms in the total Hamiltonian are expressed in a square form 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, entropy, and heat capacity of the system are deduced. In a first step, the formalism is numerically applied to the schematic Richardson model. In a second step, the method is applied to nuclei with
2025, 49(8): 084102. doi: 10.1088/1674-1137/add10b
Abstract:
In a previous study [A. H. Al-Ghamdi et al., JTUSCI 16 (2022) 1026], we comprehensively analyzed elastic scattering angular distributions (ADs) for the 7Li+28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal and breakup, by examining the energy dependence of volume integrals across various interaction potentials. In the present study, we extended this previous research 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 used 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, was generated using the trivially equivalent local potential (TELP) approach and successfully employed to reproduce the 7Li + 28Si AD 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.
In a previous study [A. H. Al-Ghamdi et al., JTUSCI 16 (2022) 1026], we comprehensively analyzed elastic scattering angular distributions (ADs) for the 7Li+28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal and breakup, by examining the energy dependence of volume integrals across various interaction potentials. In the present study, we extended this previous research 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 used 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, was generated using the trivially equivalent local potential (TELP) approach and successfully employed to reproduce the 7Li + 28Si AD 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.
2025, 49(8): 084103. doi: 10.1088/1674-1137/add872
Abstract:
The effects of nucleon-nucleon short-range correlations leading to the high-momentum tail (HMT) in the nucleon momentum distribution are studied using the isospin- and momentum-dependent Lanzhou quantum molecular dynamics (LQMD) transport model. Based on the transport model, we study the effects of the HMT of the nucleon momentum distribution on 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}}$\end{document} ![]()
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\begin{document}$ ^{124} {\rm{Sn}}$\end{document} ![]()
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\begin{document}$ ^{124} {\rm{Sn}}$\end{document} ![]()
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\begin{document}$ ^3 {\rm{He}}$\end{document} ![]()
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The effects of nucleon-nucleon short-range correlations leading to the high-momentum tail (HMT) in the nucleon momentum distribution are studied using the isospin- and momentum-dependent Lanzhou quantum molecular dynamics (LQMD) transport model. Based on the transport model, we study the effects of the HMT of the nucleon momentum distribution on 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
2025, 49(8): 084104. doi: 10.1088/1674-1137/add70f
Abstract:
In this study, we employ the maximum likelihood estimator (MLE) to investigate the relationship between initial-state fluctuations and final-state anisotropies in relativistic heavy-ion collisions. The granularity of the initial state, reflecting fluctuations in the initial conditions (ICs), is modeled using a peripheral tube model. In addition to differential flow, our analysis focuses on a class of more sensitive observables known as flow factorization. Specifically, we evaluate these observables using the MLE, an asymptotically normal and unbiased tool in standard statistical inference. Our findings show that the resulting differential flow remains essentially unchanged for different ICs defined by the peripheral tube model. The resulting harmonic coefficients obtained using the MLE and multi-particle cumulants are found to be consistent. However, the calculated flow factorizations show significant variations depending on both the IC and estimators, which is attributed to their sensitivity to initial-state fluctuations. Thus, we argue that the MLE offers a compelling alternative to standard methods, such as multi-particle correlators, particularly for sensitive observables constructed from higher moments of the azimuthal distribution.
In this study, we employ the maximum likelihood estimator (MLE) to investigate the relationship between initial-state fluctuations and final-state anisotropies in relativistic heavy-ion collisions. The granularity of the initial state, reflecting fluctuations in the initial conditions (ICs), is modeled using a peripheral tube model. In addition to differential flow, our analysis focuses on a class of more sensitive observables known as flow factorization. Specifically, we evaluate these observables using the MLE, an asymptotically normal and unbiased tool in standard statistical inference. Our findings show that the resulting differential flow remains essentially unchanged for different ICs defined by the peripheral tube model. The resulting harmonic coefficients obtained using the MLE and multi-particle cumulants are found to be consistent. However, the calculated flow factorizations show significant variations depending on both the IC and estimators, which is attributed to their sensitivity to initial-state fluctuations. Thus, we argue that the MLE offers a compelling alternative to standard methods, such as multi-particle correlators, particularly for sensitive observables constructed from higher moments of the azimuthal distribution.
2025, 49(8): 084105. doi: 10.1088/1674-1137/adcc8c
Abstract:
The spin alignment of\begin{document}$ J/\psi $\end{document} ![]()
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The spin alignment of
2025, 49(8): 084106. doi: 10.1088/1674-1137/adcd4a
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The correlation between\begin{document}$ B(E2) $\end{document} ![]()
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\begin{document}$ B(E2;4_1^+\rightarrow2_1^+)/B(E2;2_1^+\rightarrow0_1^+)<1.0 $\end{document} ![]()
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\begin{document}$ E(4_1^+)/E(2_1^+)>2.0 $\end{document} ![]()
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\begin{document}$ S U$\end{document} ![]()
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\begin{document}$ E2 $\end{document} ![]()
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The correlation between
2025, 49(8): 084107. doi: 10.1088/1674-1137/adcf10
Abstract:
We analyzed quasifission lifetimes of superheavy elements (SHEs) in the atomic number range\begin{document}$ 104\le Z\le 120 $\end{document} ![]()
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\begin{document}$ 243\le A\le 301 $\end{document} ![]()
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\begin{document}$ ^{249}_{145} $\end{document} ![]()
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\begin{document}$ ^{248}_{143} $\end{document} ![]()
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\begin{document}$ ^{260}_{154} $\end{document} ![]()
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\begin{document}$ ^{263}_{156} $\end{document} ![]()
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We analyzed quasifission lifetimes of superheavy elements (SHEs) in the atomic number range
2025, 49(8): 084108. doi: 10.1088/1674-1137/add9f9
Abstract:
Based on the extended projected shell model − a microscopic nuclear many-body theory − our recently published article [Phys. Rev. Lett. 129, 042502 (2022)] found an unexpected phenomenon (\begin{document}$ \Delta I = 2 $\end{document} ![]()
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\begin{document}$ ^{156} {\rm{Gd}}$\end{document} ![]()
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\begin{document}$ ^{156} {\rm{Gd}}$\end{document} ![]()
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\begin{document}$ ^{156} {\rm{Gd}}$\end{document} ![]()
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\begin{document}$ \Delta I = 2 $\end{document} ![]()
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Based on the extended projected shell model − a microscopic nuclear many-body theory − our recently published article [Phys. Rev. Lett. 129, 042502 (2022)] found an unexpected phenomenon (
2025, 49(8): 084109. doi: 10.1088/1674-1137/add9fc
Abstract:
Physics-Informed Neural Networks (PINNs) have emerged as a powerful tool for solving high-dimensional partial differential equations and have demonstrated promising results across various fields of physics and engineering. In this paper, 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 good 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 and have demonstrated promising results across various fields of physics and engineering. In this paper, 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 good 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.
2025, 49(8): 085101. doi: 10.1088/1674-1137/add114
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 magnetic field of the Milky Way. 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 resolutions could achieve sensitivity to photon-ALP couplings as low as\begin{document}$ g_{a\gamma} \approx 1.61 \times 10^{-13}\; \mathrm{GeV}^{-1} $\end{document} ![]()
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\begin{document}$ m_a \lesssim 10^{-9}\; \mathrm{eV} $\end{document} ![]()
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\begin{document}$ g_{a\gamma} $\end{document} ![]()
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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 magnetic field of the Milky Way. 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 resolutions could achieve sensitivity to photon-ALP couplings as low as
2025, 49(8): 085102. doi: 10.1088/1674-1137/add9fb
Abstract:
The rotational metric provides an exact solution to Einstein's clock-rate problem in curved spacetime, specifically, whether time flows more slowly at the equator of a compact object such as a neutron star than at its poles. It features a curvature singularity, an event horizon, a potentially evolving ergosphere, a rigidly-rotating normal space, and two stationary limit surfaces. Although derived from the Schwarzschild metric through rotational transformations, it includes an additional ergosphere. Given the equivalence of inertia and gravity, this demonstrates how non-inertial transformations, such as rotational transformations, can introduce new spacetime structures into a gravitational system. In particular, the additional physical degrees of freedom carried by rotational transformations are eaten by the gravitational system to form an additional ergosphere. Furthermore, the rotational metric effectively models a rigidly-rotating gravitational system and is applicable for describing rotationally-induced gravitational effects in various rotating magnetospheres.
The rotational metric provides an exact solution to Einstein's clock-rate problem in curved spacetime, specifically, whether time flows more slowly at the equator of a compact object such as a neutron star than at its poles. It features a curvature singularity, an event horizon, a potentially evolving ergosphere, a rigidly-rotating normal space, and two stationary limit surfaces. Although derived from the Schwarzschild metric through rotational transformations, it includes an additional ergosphere. Given the equivalence of inertia and gravity, this demonstrates how non-inertial transformations, such as rotational transformations, can introduce new spacetime structures into a gravitational system. In particular, the additional physical degrees of freedom carried by rotational transformations are eaten by the gravitational system to form an additional ergosphere. Furthermore, the rotational metric effectively models a rigidly-rotating gravitational system and is applicable for describing rotationally-induced gravitational effects in various rotating magnetospheres.
2025, 49(8): 085103. doi: 10.1088/1674-1137/adcc89
Abstract:
We investigate the entanglement harvesting protocol within the context of cylindrical gravitational waves given first by Einstein and Rosen, focusing on the interactions between nonrelativistic 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 distance to wave sources that emits gravitational waves and analyze 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 nonrelativistic 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 distance to wave sources that emits gravitational waves and analyze detectability using quantum Fisher information. The enhanced detectability demonstrates the advantages of cylindrical symmetric gravitational waves.
2025, 49(8): 085104. doi: 10.1088/1674-1137/add10e
Abstract:
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.
2025, 49(8): 085105. doi: 10.1088/1674-1137/ade49f
Abstract:
Gravity is identical to curved spacetime. It is manifested by the curvature of a Riemannian spacetime in general relativity but by torsion or non-metricity in teleparallel gravity models. In this paper, we apply these multiple options to the spacetime perturbation theory and seek the possibilities of representing the gravitation of the background and that of the perturbation in separate ways. We show that the perturbation around a Riemannian background can be described by torsion or non-metricity, so that we have teleparallel like actions for the perturbation.
Gravity is identical to curved spacetime. It is manifested by the curvature of a Riemannian spacetime in general relativity but by torsion or non-metricity in teleparallel gravity models. In this paper, we apply these multiple options to the spacetime perturbation theory and seek the possibilities of representing the gravitation of the background and that of the perturbation in separate ways. We show that the perturbation around a Riemannian background can be described by torsion or non-metricity, so that we have teleparallel like actions for the perturbation.
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