## Just Accepted

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Published:   , doi: 10.1088/1674-1137/ac945b
Abstract:
The cosmic distance duality relation (DDR) is constrained from the combination of type-Ia supernovae (SNe Ia) and strong gravitational lensing (SGL) systems using deep learning method. To make use of the full SGL data, we reconstruct the luminosity distance from SNe Ia up to the highest redshift of SGL using deep learning, then it is compared with the angular diameter distance obtained from SGL. Considering the influence of lens mass profile, we constrain the possible violation of DDR in three lens mass models. Results show that in the SIS model and EPL model, DDR is violated at high confidence level, with the violation parameter \begin{document}$\eta_0=-0.193^{+0.021}_{-0.019}$\end{document} and \begin{document}$\eta_0=-0.247^{+0.014}_{-0.013}$\end{document}, respectively. In the PL model, however, DDR is verified within 1σ confidence level, with the violation parameter \begin{document}$\eta_0=-0.014^{+0.053}_{-0.045}$\end{document}. Our results demonstrate that the constraints on DDR strongly depend on the lens mass models. Given a specific lens mass model, DDR can be constrained at a precision of \begin{document}$O(10^{-2})$\end{document} using deep learning.
Published:   , doi: 10.1088/1674-1137/ac93ed
Abstract:
In this work, we systematically investigate the two-pseudoscalar meson systems with the Bethe-Salpeter equation in the ladder and instantaneous approximations. By solving the Bethe-Salpeter equation numerically with the kernel containing the one-particle exchange diagrams, we find that the \begin{document}$K\bar{K}$\end{document}, \begin{document}$DK$\end{document}, \begin{document}$B\bar{K}$\end{document}, \begin{document}$D\bar{D}$\end{document}, \begin{document}$B\bar{B}$\end{document}, \begin{document}$BD$\end{document}, \begin{document}$D\bar{K}$\end{document}, \begin{document}$BK$\end{document}, and \begin{document}$B\bar{D}$\end{document} systems with \begin{document}$I=0$\end{document} can exist as bound states. We also study the contributions from heavy meson (\begin{document}$J/\psi$\end{document} and Υ) exchanges, and we find that the contribution from heavy meson exchange can not be ignored.
Published:   , doi: 10.1088/1674-1137/ac936b
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We study the deep inelastic scattering (DIS) of a proton-targeted lepton in the presence of gluon condensation using gauge/gravity duality. We use a modified \begin{document}$AdS_5$\end{document} background where the modification parameter c corresponds to the gluon condensation in the boundary theory. Firstly, when examining the electromagnetic field, we find that non-zero c can increase the magnitude of the field. Our goal is to find the acceptable value of c for this scattering and our method is based on setting the mass of the proton as an eigenvalue of the baryonic state equations of the DIS to find the acceptable value of the parameter c on the other side of the equations. Therefore in the second step, we calculate wave function equations for the baryonic states where the mass of the proton target requires a value contribution of c as \begin{document}$c=0.0120 \; \rm GeV^4$\end{document}. Proceeding by the electromagnetic field and the baryonic states, we derive the holographic interaction action related to the amplitude of the scattering. Finally, we compute the corresponding structure functions numerically as functions of x and q, which are Björken variables and the lepton momentum transfers, respectively. Comparing the Jlab Hall C data with our theoretical calculations, our results are acceptable.
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We study a double covering of modular \begin{document}$A_4$\end{document} flavor symmetry in which we construct lepton models in cases of canonical seesaw and radiative seesaw models. Thanks to irreducible doublet representations, heavier Majorana fermion masses are characterized by one free parameter that would differentiate from \begin{document}$A_4$\end{document} symmetry. Through χ square numerical analysis, we find that both scenarios have some predictions in case of normal hierarchy reproducing neutrino oscillation data. But, we would not find any solutions to satisfy the neutrino oscillation data in case of radiative seesaw of inverted hierarchy.
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We study the dependence of the transverse mass distribution of the charged lepton and the missing energy on the parton distributions (PDFs) adapted to the W boson mass measurements at the CDF and ATLAS experiments. We compare the shape variations of the distribution induced by different PDFs, and find that spread of predictions from different PDF sets can be much larger than the PDF uncertainty predicted by a specific PDF set. We suggest analyzing the experimental data using up-to-date PDFs for better understanding of the PDF uncertainties in the W boson mass measurements. We further carry out a series of Lagrange multiplier scans to identify the constraints on the transverse mass distribution imposed by individual data sets in the CT18 global analysis. In the case of CDF measurement, the distribution is mostly sensitive to the d-quark PDFs at intermediate x region that are largely constrained by the DIS and Drell-Yan data on deuteron target, as well as the Tevatron lepton charge asymmetry data.
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A partial wave scattering matrix for the total effective complex potential of nucleus nucleus collisions is used to handily analyze the angular variations of elastic scattering and fusion cross-sections simultaneously with a unique potential. The expectation value of the imaginary part of the potential calculated using the distorted waves from the full potential in the elastic channel accounts for \begin{document}$\sigma_r$\end{document}. This is equated as the sum of the cross-sections due to absorption in different regions of the potential where the imaginary part is actively present. The potential is taken as energy independent and its weakly absorbing nature, which supports the resonance states in various partial wave trajectories. Therefore, these resonances show oscillatory behavior changes with respect to energy \begin{document}$D(E_{c.m.})=\dfrac{d^{2}(E_{c.m.}\sigma_{fus})}{dE_{c.m.}^{2}}$\end{document}. In this paper, we have successfully discussed the elastic scattering and fusion cross-sections simultaneously with the results of \begin{document}$D(E_{c.m.})$\end{document} for \begin{document}$^{16}O+^{92}Zr$\end{document} system.
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We make a detailed study on the properties of the total decay width of Higgs decay channel \begin{document}$H\to gg$\end{document} up to \begin{document}$\alpha_s^6$\end{document}-order QCD corrections by using the newly suggested infinite-order scale-setting approach, which is based on the ideas of both the principle of maximum conformality and the intrinsic conformality. This approach is called as the PMC\begin{document}$_\infty$\end{document} approach. By using the PMC\begin{document}$_\infty$\end{document} approach, we observe that the conventional renormalization scale ambiguity in perturbative QCD calculation is eliminated and the residual scale dependence due to unknown higher-order terms can also be highly suppressed. We then obtain an accurate perturbative QCD prediction on the total decay width, e.g. \begin{document}$\Gamma (H \to gg)|_{\rm PMC_\infty} =336.42^{+7.01}_{-6.92}$\end{document} KeV, where the errors are squared averages of those from all the mentioned error sources.
Published:   , doi: 10.1088/1674-1137/ac945c
Abstract:
The cross sections of \begin{document}$e^+e^- \rightarrow K^+K^-J/\psi$\end{document} at center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb\begin{document}$^{-1}$\end{document} data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in the line shape of the cross sections. The mass and width of the first structure are measured to be (\begin{document}$4225.3\pm2.3\pm21.5$\end{document}) MeV and (\begin{document}$72.9\pm6.1\pm30.8$\end{document}) MeV, respectively. They are consistent with those of the established \begin{document}$Y(4230)$\end{document}. The second structure is observed for the first time with a statistical significance greater than 8σ, denoted as \begin{document}$Y(4500)$\end{document}. Its mass and width are determined to be (\begin{document}$4484.7\pm13.3\pm24.1$\end{document}) MeV and (\begin{document}$111.1\pm30.1\pm15.2$\end{document}) MeV, respectively. The first presented uncertainties are statistical and the second ones are systematic. The product of the electronic partial width with the decay branching fraction \begin{document}$\Gamma(Y(4230)\to e^+ e^-) \mathcal{B}(Y(4230) \to K^+ K^- J/\psi)$\end{document} is reported.
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In this work, we observe that in the presence of the string cloud parameter a and the quintessence parameter γ, with the equation of state parameter \begin{document}$\omega_q={-2}/{3}$\end{document} the radius of the shadow of the Schwarzschild black hole increases as compared with the pure Schwarzschild black hole case. The existence of both quintessential dark energy and cloud of strings magnify the shadow size and hence the strength of the gravitational field around the Schwarzschild black hole increases. Using the data collected by the Event Horizon Telescope (EHT) collaboration for the M87* and Sgr A*, we obtain upper bounds on the values of the parameters a and γ. Further, we see the effects of the parameters a and γ on the rate of emission energy for the Schwarzschild black hole. We notice that the rate of emission energy is higher in the presence of clouds of string and quintessence. Moreover, we study the weak deflection angle using the Gauss-Bonnet theorem. We show the influence of the cloud of string parameter a and the quintessential parameter γ on the weak deflection angle. We notice that both the parameters a and γ increase the deflection angle α.
Published:   , doi: 10.1088/1674-1137/ac8cd5
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The W mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at 7σ level. We discuss a few possible interpretations and their collider implications. We perform electroweak global fits under various frameworks and assumptions. We consider three types of electroweak global fits in the effective-field-theory framework: the S-T, the S-T-\begin{document}$\delta G_F$\end{document}, and the eight-parameter flavor-universal one. We discuss the amounts of tensions between different \begin{document}$m_W$\end{document} measurements reflected in these fits and the corresponding shifts in central values of these parameters. With these electroweak fit pictures in hand, we present a few different classes of models and discuss their compatibility with these results. We find that while explaining the \begin{document}$m_W$\end{document} discrepancy, the single gauge boson extensions face strong LHC direct search constraints unless the \begin{document}$Z'$\end{document} is fermiophobic (leptophobic) which can be realized if extra vector fermions (leptons) mix with the SM fermions (leptons). Vector-like top partners can partially generate the needed shift to the electroweak observables. The compatibility with top squark is also studied in detail. We find non-degenerate top squark soft masses enhance the needed operator coefficients, enabling an allowed explanation compatible with current LHC measurements. Overall, more theory and experimental developments are highly in demand to reveal the physics behind this discrepancy.
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In this paper, we investigate the influence of the angular momentum of a charged particle around non-extremal and extremal Einstein-Maxwell-Dilaton-Axion black holes on the Lyapunov exponent. The angular momentum's ranges and spatial regions where the bound of the exponent is violated are found for certain values of the rotation parameter and dilatonic constant of the black holes. This violation always exists when the rotation parameter is large enough and the rotation directions of the particle is opposite to those of the black holes. The spatial regions outside the extermal black hole for the violation is relatively large. In the near-horizon regions of the extremal black holes, the violation depends on the rotation directions of the black holes and particle, and does not depend on the value of the angular momentum.
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In this work, the microstructure of charged AdS black holes under minimal length effects is investigated. We study the thermodynamics of black holes in the extended phase space, where the cosmological constant is regarded as the thermodynamic pressure. The modified Hawking temperature and phase transition are obtained based on the generalized uncertainty principle (GUP). Then, using thermodynamic geometry, the microstructure of black holes can be determined by the ratio of GUP parameter to charge. For a small ratio, the black hole exhibits the typical RN-AdS microstructure with van der Waals phase transition and repulsive/attractive interactions. As the ratio increases, the reentrant phase transition takes place, and both the repulsion-attraction coexisted black hole and the attraction dominated black hole can be found in this case. For a large ratio, the black hole behaves like a Schwarzchild-AdS black hole in which neither phase transition nor repulsive interaction exists. These results suggest that the GUP effect will reduce the repulsive interaction presented by the charged AdS black hole.
Published:   , doi: 10.1088/1674-1137/ac8c22
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In this paper, we consider an open system from the thermodynamic perspective for an adiabatic FRW universe model in which particle creation occurs within the system. In that case, the modified continuity equation is obtained and then we correspond it to the continuity equation of \begin{document}$f(T)$\end{document} gravity. So, we take \begin{document}$f(T)$\end{document} gravity with the viscous fluid in flat-FRW metric, in which T is the torsion scalar. We consider the contents of the universe to be dark matter and dark energy and consider an interaction term between them. The interesting point of this study is that we make equivalent the modified continuity equation resulting from the particle creation with the matter continuity equation resulting from \begin{document}$f(T)$\end{document} gravity. The result of this evaluation creates a relationship between the number of particles and the scale factor. In what follows, we write the corresponding cosmological parameters in terms of the number of particles and also reconstruct the number of particles in terms of the redshift parameter, then We parameterize the Hubble parameter derived from power-law cosmology with 51 data from the Hubble observational parameter. Next, we plot the corresponding cosmological parameters for the dark energy in terms of the redshift to investigate the accelerated expansion of the universe. In addition, by using the sound speed parameter, we discuss the stability analysis and instability analysis of the present model in different eras of the universe. Finally, we plot the density parameter values for dark energy and dark matter in terms of the redshift parameter.
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In this work we study the quasi-two-body decays \begin{document}$B_{(s)}\to K^*\gamma\to K\pi\gamma$\end{document} in the perturbative QCD (PQCD) approach. The two-meson distribution amplitudes (DAs) are introduced to describe the final state interactions of the \begin{document}$K\pi$\end{document} pair, which involve the time-like form factors and the Gegenbauer polynomials. We calculate the CP averaged branching ratios for the decays \begin{document}$B_{(s)}\to K^*\gamma\to K\pi\gamma$\end{document}. Our results are in agreement with the newly updated data measured by Belle II. It suggests that these quasi-two-body B decays are more appropriate to be analyzed in the three-body framework than in the two-body one. We also predict the direct CP asymmetries for the considered decay modes and find that \begin{document}$A_{CP}(B_{u,d}\to K^*\gamma\to K\pi\gamma)$\end{document} are small and less than \begin{document}$1\$\end{document}% in magnitude, while \begin{document}$A_{CP}(B_{s}\to K^*\gamma\to K\pi\gamma)$\end{document} is larger and can arrive at a few percent. Our predictions can be tested by the future B meson experiments.
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We investigate generalized Jackiw-Teitelboim gravity, coupling the dilaton field with two scalar matter fields. We obtain the equations of motion of the fields and investigate the linear perturbation of the solutions in general. We study two specific situations that allow analytic solutions with topological behavior and check how the dilaton field, the warp factor and Ricci scalar behave. In particular, we have shown how the parameters can de used to modify the structure of the solutions. Moreover, the perturbations are in general described by intricate coupled differential equations, but in some specific cases we could construct the corresponding zero modes analytically.
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A three Higgs-doublet model admitting an \begin{document}$S_3$\end{document}-symmetry can predict the observed pattern of the quark masses and their mixings. However the same symmetry also introduces potential flavour-changing neutral currents at the tree level. We assume in this work that the scalar potential contains appropriate soft \begin{document}$S_3$\end{document}-breaking terms in order to keep the choices of the scalar masses flexible. We identify the parameters in the Yukawa Lagrangian in the quark sector responsible for such FCNCs and constrain them using data from some of the flavour physics observables like meson-decays and meson-mixings. We also validate the corresponding model parameter space with renormalisation group (RG) evaluation.
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The dibaryon concept for the nuclear force is presented, assuming that the main attraction between the nucleons at medium distances is determined by the s-channel exchange of an intermediate six-quark (dibaryon) state. To construct the respective NN interaction model, a microscopic six-quark description of the NN system is used, in which symmetry aspects play a special role. It is shown that the NN interaction in all important partial waves can be described properly by a superposition of the long-range t-channel one-pion exchange and the s-channel exchange by an intermediate dibaryon. The developed model gives a good description of both elastic phase shifts and inelasticities of NN scattering in all S, P, D and F partial waves at energies from zero to 600–800 MeV and even higher. The parameters of the intermediate six-quark states corresponding to the best fit of NN scattering data are found to be consistent with the parameters of the known dibaryon resonances in those NN partial configurations where their existence has been experimentally confirmed. Predictions for new dibaryon states are given as well.