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<jats:title>Abstract</jats:title> <jats:p>The reaction cross-sections of <jats:sup>124</jats:sup>Xe(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>123</jats:sup>Xe, <jats:sup>126</jats:sup>Xe(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>125</jats:sup>Xe, <jats:sup>128</jats:sup>Xe(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>127</jats:sup>Xe, <jats:sup>130</jats:sup>Xe(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>129m</jats:sup>Xe, <jats:sup>132</jats:sup>Xe(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>131m</jats:sup>Xe, <jats:sup>130</jats:sup>Xe(<jats:italic>n</jats:italic>, <jats:italic>p</jats:italic>)<jats:sup>130</jats:sup>I, <jats:sup>131</jats:sup>Xe(<jats:italic>n</jats:italic>, <jats:italic>p</jats:italic>)<jats:sup>131</jats:sup>I, and <jats:sup>132</jats:sup>Xe(<jats:italic>n</jats:italic>, <jats:italic>p</jats:italic>)<jats:sup>132</jats:sup>I were measured at the 13.5, 13.8, 14.1, 14.4, and 14.8 MeV neutron energies. The monoenergetic neutrons were generated via the <jats:sup>3</jats:sup>H(<jats:italic>d,n</jats:italic>)<jats:sup>4</jats:sup>He reaction at the China Academy of Engineering Physics using the K-400 Neutron Generator with a solid <jats:sup>3</jats:sup>H-Ti target. A high-purity germanium detector was employed to measure the activities of the product. The reactions <jats:sup>93</jats:sup>Nb(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>92m</jats:sup>Nb and <jats:sup>27</jats:sup>Al(<jats:italic>n</jats:italic>, α)<jats:sup>24</jats:sup>Na were adopted for neutron flux calibration. The cross sections of the (<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>) and (<jats:italic>n</jats:italic>, <jats:italic>p</jats:italic>) reactions of the xenon isotopes were obtained within the 13–15 MeV neutron energy range. These cross-sections were then compared with the IAEA-exchange format (EXFOR) database-derived experimental data, together with the evaluation results of the CENDL-3, ENDF/B-VIII.0, JENDL-4.0, RUSFOND, and JEFF-3.3 data libraries, as well as the theoretical excitation function obtained using the TALYS-1.95 code. The cross-sections of the reactions (except for the <jats:sup>124</jats:sup>Xe(<jats:italic>n</jats:italic>, 2<jats:italic>n</jats:italic>)<jats:sup>123</jats:sup>Xe and <jats:sup>132</jats:sup>Xe(<jats:italic>n</jats:italic>, <jats:italic>p</jats:italic>)<jats:sup>132</jats:sup>I) at 13.5, 13.8, and 14.1 MeV are reported for the first time in this study. The obtained results are beneficial in providing better cross-section constraints for the reactions in the 13–15 MeV region, thus improving the quality of the corresponding database. Meanwhile, these data can also be used for the verification of relevant nuclear reaction model parameters. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The capture cross sections of the <jats:sup>169</jats:sup>Tm <jats:inline-formula> <jats:tex-math><?CDATA $ (n, \gamma) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044002_M1.jpg" xlink:type="simple" /> </jats:inline-formula> reaction were measured at the back streaming white neutron beam line (Back-n) of the China Spallation Neutron Source (CSNS) using four C<jats:sub>6</jats:sub>D<jats:sub>6</jats:sub> liquid scintillation detectors. The background subtraction, normalization, and correction were carefully considered in the data analysis to obtain accurate cross sections. For the resonance at 3.9 eV, the <jats:italic>R</jats:italic>-matrix code SAMMY was used to determine the resonance parameters with the internal normalization method. The average capture cross sections of <jats:sup>169</jats:sup>Tm for energy between 30 and 300 keV were extracted relative to the <jats:sup>197</jats:sup>Au <jats:inline-formula> <jats:tex-math><?CDATA $ (n, \gamma) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044002_M2.jpg" xlink:type="simple" /> </jats:inline-formula> reaction. The measured cross sections of the <jats:sup>169</jats:sup>Tm <jats:inline-formula> <jats:tex-math><?CDATA $ (n, \gamma) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044002_M3.jpg" xlink:type="simple" /> </jats:inline-formula> reaction were reported in logarithmically equidistant energy bins with 20 bins per energy decade with a total uncertainty of 5.4% – 7.0% in this study and described in terms of average resonance parameters using a Hauser-Feshbach calculation with fluctuations. The point-wise cross sections and the average resonance parameters showed fair agreement with the evaluated values of the ENDF/B-VIII.0 library in the energy region studied. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>A systematic study on forward–backward (FB) multiplicity correlations from large systems to small ones through a multi-phase transport model (AMPT) has been performed and the phenomenon that correlation strength increases with centrality can be explained by taking the distribution of events as the superposition of a series of Gaussian distributions. It is also found that correlations in the <jats:inline-formula> <jats:tex-math><?CDATA $ \eta -\phi $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044101_M1.jpg" xlink:type="simple" /> </jats:inline-formula> plane can imply the shape of the event. Furthermore, long-range correlations originate from the fluctuations associated with the source information. FB correlations allow us to decouple long-range correlations from short-range correlations, and may provide a chance to investigate the <jats:italic>α</jats:italic>-clustering structure in initial colliding light nuclei as well. It seems the tetrahedron <jats:sup>16</jats:sup>O + <jats:sup>16</jats:sup>O collision gives a more uniform and symmetrical fireball, that emits the final particles more isotropically or independently in the longitudinal direction, indicating that the forward–backward multiplicity correlation could be used to identify the pattern of <jats:italic>α</jats:italic>-clustered <jats:sup>16</jats:sup>O in future experiments. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The masses of pion and sigma meson modes, along with their dissociation in the quark medium, provide detailed spectral structures of the chiral partners. Collectivity has been observed in pA and pp systems both at LHC and RHIC. In this research, we studied the restoration of chiral symmetry by investigating the finite size effect on the detailed structure of chiral partners in the framework of the Nambu-Jona-Lasinio model. Their diffusion and conduction have been studied using this dissociation mechanism. It is determined that the masses, widths, diffusion coefficients, and conductivities of chiral partners merge at different temperatures in the restoration phase of chiral symmetry. However, merging points are shifted to lower temperatures when finite size effect is introduced into the picture. The strengths of diffusions and conductions are also reduced once the finite size is introduced in the calculations.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The study of nuclear mass is very important, and the neural network (NN) approach can be used to improve the prediction of nuclear mass for various models. Considering the number of valence nucleons of protons and neutrons separately in the input quantity of the NN model, the root-mean-square deviation of binding energy between data from AME2016 and liquid drop model calculations for 2314 nuclei was reduced from 2.385 MeV to 0.203 MeV. In addition, some defects in the Weizsäcker–Skyrme (WS)-type model were repaired, which well reproduced the two-neutron separation energy of the nucleus synthesized recently by RIKEN RI Beam Factory [Phys. Rev. Lett. <jats:bold>125</jats:bold>, (2020) 122501]. The masses of some of the new nuclei appearing in the latest atomic mass evaluation (AME2020) are also well reproduced. However, the results of neural network methods for predicting the description of regions far from known atomic nuclei need to be further improved. This study shows that such a statistical model can be a tool for systematic searching of nuclei beyond existing experimental data. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>By adopting different neutron and proton density distributions, cluster decay half-lives were investigated using double-folding potentials with constant and nuclear asymmetry dependent sets of nuclear density parameters. Two adopted asymmetry dependent sets of parameters were fitted based on microscopic calculations, and they were calculated based on the neutron skin/halo-type nuclei assumption and by employing experimental rms charge radii. A bulk agreement between theory and experiment was obtained for all sets of parameters using a calculated cluster preformation probability. Few differences were observed between the skin and halo-type assumptions. However, the notable role of the asymmetry parameter was observed in the relatively large differences between the skin and skin-type with zero thickness.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A microscopic description of the low-lying positive-parity rotational bands in <jats:sup>20</jats:sup>Ne is given within the framework of the symplectic-based proton-neutron shell-model approach provided by the proton-neutron symplectic model (PNSM). For this purpose, a model Hamiltonian is adopted. This includes an algebraic interaction lying in the enveloping algebra of the <jats:inline-formula> <jats:tex-math><?CDATA $ Sp(12,R) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044105_M1.jpg" xlink:type="simple" /> </jats:inline-formula> dynamical group of the PNSM, which introduces both horizontal and vertical mixings of different <jats:inline-formula> <jats:tex-math><?CDATA $ SU(3) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044105_M2.jpg" xlink:type="simple" /> </jats:inline-formula> irreducible representations within the <jats:inline-formula> <jats:tex-math><?CDATA $ Sp(12,R) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044105_M3.jpg" xlink:type="simple" /> </jats:inline-formula> irreducible collective space of <jats:sup>20</jats:sup>Ne. A good overall description is obtained for the excitation energies of the ground and first two excited <jats:italic>β</jats:italic> bands, including the ground state intraband <jats:inline-formula> <jats:tex-math><?CDATA $ B(E2) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044105_M4.jpg" xlink:type="simple" /> </jats:inline-formula> quadrupole collectivity and the known interband <jats:inline-formula> <jats:tex-math><?CDATA $ B(E2) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_044105_M5.jpg" xlink:type="simple" /> </jats:inline-formula> transition probabilities between the low-lying collective states, without utilizing an effective charge. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Considering the preformation probability of the two emitted protons in the parent nucleus, we extend the Coulomb and proximity potential model (CPPM) to systematically study two-proton (2<jats:italic>p</jats:italic>) radioactivity half-lives of the nuclei close to proton drip line. The proximity potential chosen is Prox. 81 proposed by Blocki <jats:italic>et al</jats:italic>. in 1981. Furthermore, we apply this model to predict the half-lives of possible 2<jats:italic>p</jats:italic> radioactive candidates whose 2<jats:italic>p</jats:italic> radioactivity is energetically allowed or observed but not yet quantified in the evaluated nuclear properties table NUBASE2016. The predicted results are in good agreement with those from other theoretical models and empirical formulas, namely the effective liquid drop model (ELDM), generalized liquid drop model (GLDM), Gamow-like model, Sreeja formula and Liu formula. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>This study explores the scalar and Dirac quasinormal modes pertaining to a class of black hole solutions in the scalar-tensor-Gauss-Bonnet theory. The black hole metrics in question are novel analytic solutions recently derived in the extended version of the theory, which effectively follows at the level of the action of string theory. Owing to the existence of a nonlinear electromagnetic field, the black hole solution possesses a nonvanishing magnetic charge. In particular, the metric is capable of describing black holes with distinct characteristics by assuming different values of the ADM mass and the magnetic charge. This study investigates the scalar and Dirac perturbations in these black hole spacetimes; in particular, we focus on two different types of solutions, based on distinct horizon structures. The properties of the complex frequencies of the obtained dissipative oscillations are investigated, and the stability of the metric is subsequently addressed. We also elaborate on the possible implications of this study.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We propose a two-component dark matter explanation to the EDGES 21 cm anomalous signal. The heavier dark matter component is long-lived, and its decay is primarily responsible for the relic abundance of the lighter dark matter, which is millicharged. To evade the constraints from CMB, underground dark matter direct detection, and XQC experiments, the lifetime of the heavier dark matter has to be larger than <jats:inline-formula> <jats:tex-math><?CDATA $ 0.1\, \tau_U $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_045102_M1.jpg" xlink:type="simple" /> </jats:inline-formula>, where <jats:inline-formula> <jats:tex-math><?CDATA $ \tau_U $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_4_045102_M2.jpg" xlink:type="simple" /> </jats:inline-formula> is the age of the universe. Our model provides a viable realization of the millicharged dark matter model to explain the EDGES 21 cm signal, since the minimal model in which the relic density is generated via thermal freeze-out has been ruled out by various constraints. </jats:p>