In the present work, we examine the sensitivity of nuclear matrix elements (NMEs) for light neutrino-exchange mechanism of neutrinoless double beta decay ($0\nu \beta \beta$) of ${}^{48}\mathrm{Ca}$ to the central, spin-orbit, and tensor components of two-nucleon interaction. The NMEs are calculated in the nuclear shell-model framework in $fp$-model space using frequently used GXPF1A interaction and a new effective interaction named GX1R of $pf$ shell. The decomposition of the shell-model two-nucleon interactions into their individual components is performed using spin-tensor decomposition. The NMEs are calculated in closure approximation by using optimal value of the closure energy. The results shows that the total NMEs calculated with the central component of the interactions are of positive sign. By adding spin-orbit part to central part of the interactions, sign of the total NMEs gets change, and in absolute value, NMEs decreases by about $15\text{–}18\%$. Sign change in total NMEs are again seen by adding tensor part to the $\text{central}+\text{spin}-\text{orbit}$ part of the interactions. Similar trends of sign change are also observed for Fermi, Gamow-Teller, and tensor matrix elements. Thus we infer that SO and T part mostly cancel the effects of each other in NMEs calculations. For both the interactions, the total NMEs calculated with the C part is found to be $20\%$ enhanced as compared to the NMEs calculated with the total interactions. With new GX1R interaction, there is about $1\text{–}3\%$ increments in the total NMEs as compared to NMEs with GXPF1A interaction. This increments comes from the modifications of isospin $T=1$ tensor force two-nucleon matrix elements to bring the characteristic properties of tensor force into the GX1R interaction.

Aiming at understanding the production mechanism of new neutron-rich nuclei around $N=126$, the multinucleon transfer reaction ${}^{136}\mathrm{Xe}+{}^{208}\mathrm{Pb}$ at $E_{\mathrm{c}.\mathrm{m}.}=450$ MeV has been investigated in the framework of the three-dimensional time-dependent Hartree-Fock (TDHF) theory and a statistical model GEMINI. The calculated production cross sections of the targetlike fragments are compared with the experimental data. The model predictions can well describe the yields of nuclei near the target. The reactions of ${}^{132}\mathrm{Sn}+{}^{208}\mathrm{Pb}$ at different incident energies above the Coulomb barrier are also studied. It is shown that this system is a better candidate for producing $N=126$ neutron-rich nuclei than using ${}^{136}\mathrm{Xe}$ as the projectile because of the favored proton pickup and neutron stripping transfer channels. The study of de-excitation effect indicates that the suitable incident energy to synthesize neutron-rich nuclei should be just above the Coulomb barrier. It is also found in ${}^{132}\mathrm{Sn}+{}^{208}\mathrm{Pb}$ that about 50 new neutron-rich nuclei with the production cross sections larger than ${10}^{-6}$ mb are obtained dominantly through quasifission and deep-inelastic collisions. However, those with $N=126$ are mainly from grazing collisions. Comparison with the results of the GRAZING model is also discussed.

Central lead-lead collisions at energies available at the CERN Large Hadron Collider (LHC) may pose a particular challenge for jet identification as multiple jets are produced per each collision event. We simulate the jet evolution in central PbPb events at $\sqrt{s_{NN}}=2.76\mathrm{GeV}$ collision energy with the epos3 initial state, which typically contains multiple hard scatterings in each event. Therefore the partons from different jets have a significant chance to overlap in momentum space. We find that 30% of the jets with $p_{\perp }>50\mathrm{GeV}$, identified by the standard anti-$k_{\perp }$ jet finding algorithm with jet cone size $R=0.3$, contain “intruder” particles from overlapping generator-level jets. This fraction increases with increasing beam energy and increasing $R$. The reconstructed momentum of the jet differs from that of the modeled jet by the loss due to jet partons which are outside of the jet cone and by the gain due to intruder partons. The sum of both may be positive or negative. These intruder partons particularly affect the radial jet momentum distribution because they contribute mostly at large angles $\mathrm{\Delta }r$ with respect to the jet center. The study stresses the importance of the jet overlap effect emerging in central lead-lead collisions at LHC energies, while being negligible in peripheral PbPb or $p\mathrm{Pb}/pp$ collisions.

In this work, we study the interactions of bottom mesons which lead to $\mathrm{{\rm Y}}$ production and absorption in hot hadronic matter. We use effective Lagrangians to calculate the $\mathrm{{\rm Y}}$ production cross section in processes such as ${\overline{B}}^{(*)}+B^{(*)}\to \mathrm{{\rm Y}}+(\pi ,\rho )$ and also the $\mathrm{{\rm Y}}$ absorption cross section in the corresponding inverse processes. We update and extend previous calculations by Lin and Ko, introducing anomalous interactions. The obtained cross sections are used as input to solve the rate equation which allows us to follow the time evolution of the $\mathrm{{\rm Y}}$ multiplicity. In contrast to previous conjectures, our results suggest that the interactions in the hadron gas phase reduce the $\mathrm{{\rm Y}}$ abundance.

Nuclei with static intrinsic octupole deformation or a soft octupole vibrational mode lead to strongly enhanced collective nuclear Schiff moments. This paper investigates octupole deformations in stable and very long lifetime nuclei such as ${}^{153}\mathrm{Eu},{}^{235}\mathrm{U},{}^{237}\mathrm{Np}$, and ${}^{227}\mathrm{Ac}$. The estimates of the enhanced Schiff moments, atomic electric dipole moments, and T,P-odd interaction constants in molecules containing these nuclei are presented. Corresponding experiments may be used to test CP-violation theories predicting T,P-violating nuclear forces and to search for axions.

The spectroscopic properties of the odd-odd isotopes ${}^{124–132}\mathrm{Cs}$ have been studied within the interacting boson-fermion-fermion model based on the Gogny-D1M energy density functional framework. Major ingredients to build the interacting boson-fermion-fermion Hamiltonian, such as the $\left(\beta ,\gamma \right)$-deformation energy surfaces for the even-even core nuclei ${}^{124–132}\mathrm{Xe}$ as well as single-particle energies and occupation probabilities of the odd nucleons, have been computed microscopically with the constrained Hartree-Fock-Bogoliubov method. A few coupling constants of the boson-fermion and residual neutron-proton interactions are fitted to reproduce with a reasonable accuracy the experimental excitation energy of the low-lying levels of the odd-mass and odd-odd nuclei. The method is applied to describe the low-energy low-spin spectra of the odd-odd Cs nuclei and the band structures of higher-spin higher-energy states, mainly based on the ${\left(\nu h_{11/2}\right)}^{-1}\otimes \pi h_{11/2}$ configuration. Many of those odd-odd Cs nuclei have been identified as candidates for exhibiting chiral doublet bands.

Time evolution of shear viscosity $\eta$, entropy density $s$, and their ratio $\eta /s$ in the central area of central gold-gold collisions at energies available at the Nuclotron-based Ion Collider fAcility (NICA) are studied within the ultrarelativistic quantum molecular dynamics (UrQMD) transport model. The extracted values of energy density, net baryon density, and net strangeness density are used as input to (i) the statistical model of an ideal hadron gas to define temperature, baryochemical potential, and strangeness chemical potential, and to (ii) a UrQMD box with periodic boundary conditions to study the relaxation process of highly excited matter. During the relaxation stage, the shear viscosity is determined in the framework of the Green-Kubo approach. The procedure is performed for each of 20 time slices, corresponding to conditions in the central area of the fireball at times from 1 to $20\mathrm{fm}/c$. For all tested energies the ratio $\eta /s$ reaches its minimum, ${\displaystyle {\left(\eta /s\right)}_{\min }\approx 0.3}$ at $t\approx 5\mathrm{fm}/c$. Then it increases up to the late stages of the system evolution. This rise is accompanied by the drop of both temperature and strangeness chemical potential and by the increase of baryochemical potential.

In this paper, we calculate the mass shift and decay constant of isospin-averaged pseudoscalar $(D^{+},D^0)$ and scalar $(D_0^{+},D_0^0)$ mesons by the magnetic-field-induced quark and gluon condensates at finite density and temperature of asymmetric nuclear matter. We have calculated the in-medium chiral condensates from the chiral $\mathrm{SU}\left(3\right)$ mean-field model and subsequently used these condensates in QCD sum rules to calculate the effective mass and decay constant of $D$ mesons. Consideration of external magnetic-field effects in hot and dense nuclear matter lead to appreciable modification in the masses and decay constants of $D$ mesons. Furthermore, we also studied the effective decay width of higher charmonium states $[\psi \left(3686\right),\psi \left(3770\right),{{\chi }_c}_0\left(3414\right),{{\chi }_c}_2\left(3556\right)]$ as a by-product by using the ${}^3\mathrm{P}_0$ model, which can have an important impact on the yield of $J/\psi$ mesons. The results of the present work will be helpful to understand the experimental observables of heavy-ion colliders which aim to produce matter at finite density and moderate temperature.

The tensor force, as an important component of strong nuclear force, generates a variety of intriguing effects ranging from few-body systems to neutron stars. It is responsible for the nucleon-nucleon correlation beyond mean-field approximation, and is accordingly proved to play no role in the standard Skyrme energy density functionals in the present work. Therefore, the Skyrme original tensor interaction that is extensively employed presently is invalid. As an alternative strategy, we introduced a central interaction, i.e., the ${\mathit{\sigma }}_1·{\mathit{\sigma }}_2$ term, to improve the description of experimental single-particle structure, and, to address its effect, we established two Skyrme interactions IMP1 and IMP2 complemented by the calibrated charge-violating interactions. The central ${\mathit{\sigma }}_1·{\mathit{\sigma }}_2$ interaction turns out to substantially improve the description of shell evolution in Sn isotopes and $N=82$ isotones.

We study the excitation energy-dependent potential-energy surfaces (PESs) for both the spherical and deformed fragments from the ternary fragmentation (TF) of ${}^{252}\mathrm{Cf}$ at four different excitation energies of the fissioning parent nuclei. A two-dimensional minimization approach with respect to the charge numbers ($Z_1, Z_2$, and $Z_3$) of the fragments has been used to minimize all possible ternary combinations, which are generated from the atomic-mass-evaluation (AME2016) data [Chin. Phys. C 41, 030003 (2017)]. To calculate the energy-dependent TF-PES, we used the temperature-dependent binding energies (TDBE), which are calculated as follows: the temperature-dependent ($T$-dependent) macroscopic liquid-drop model (LDM) energy proper due to Krappe's formula [Phys. Rev. C 59, 2640 (1999)] and the microscopic shell correction energies due to the analytical estimates of Myers and Swiatecki [Nucl. Phys. 81, 1 (1966)]. Furthermore, the shell correction energies and the nuclear deformations are also made $T$-dependent. In this study, the $T$-dependent total interaction potential between the ternary fragments is calculated for the fragments in a collinear geometry with the lightest fragment $A_3$ being in the middle of the two main fission fragments $A_1$ and $A_2$. From the TF-PES results with the use of spherical-shell corrections, a strong energy maximum in the PES is obtained around $Z_3=2$ with the $Z_1=50$ region due to the closed-shell effects of doubly magic nuclei. In addition to this, we also obtained some other significant energy maxima around the magic and/or semimagic numbers of nuclei. These energy maxima extend further with increasing excitation energy of the fissioning parent nuclei. We also found that the true-ternary-fragmentation (TTF) fragments are reasonably favored at high excitation energies. Furthermore, the effects of $T$-dependent deformations and the $T$-dependent deformed-shell corrections in the TF-PES of ${}^{252}\mathrm{Cf}$ are also studied. From the TF-PES results of deformed ternary fragments, we obtained the energy maximum around $Z_3=16$ region, which may be due to the larger ${\beta }_2$ deformation values. Furthermore, we also studied the ternary fragmentation yields and neutron emission from the excited fragments in the ${}^{10}\mathrm{Be}$-accompanied spontaneous ternary fission of ${}^{252}\mathrm{Cf}$ and compared our calculated results with the available experimental data.

Background: The nuclear charge radii provide direct information for the nuclear structures. In recent years, many pioneering researches have been devoted to the nuclear charge radii based on the Bayesian neural networks (BNN) method.

Purpose: The neural networks always have complex structure. To analyze the data relationships clearly, a statistical method is introduced to study the nuclear properties by combining the sophisticated nuclear models with the naive Bayesian probability (NBP) classifier.

Method: In the framework of the NBP method, the predicted charge radii are interpreted as the most reasonable expectations. The prior probabilities and the condition probabilities are computed by the experimental data and the raw results of nuclear models. The posterior probabilities of expectations are updated by the Bayesian formula. The predicted charge radii are regarded as the expectations with maximum probability. Moreover, the abilities of global optimizations and extrapolations of the NBP method are analyzed to demonstrate the availability of the NBP method.

Results: For the HFB model and the semiempirical formula, the accuracy of charge radii predictions improves $41\%$ and $32\%$ after NBP refinements, respectively. Calculations also illustrate that the NBP method has robust extrapolating abilities, and the charge radii of unknown regions in the nuclear chart can be predicted by the NBP method.

Conclusions: The NBP method contains the advantages of local relations and global descriptions, which can provide fine-tuning for the theoretical results of sophisticated nuclear models. The method proposed in this paper can also be used for other research of nuclear properties.

Production cross sections for ${}^{209}\mathrm{Bi}$(p, xn)${}^{207,206,205,204}\mathrm{Po}$ and ${}^{209}\mathrm{Bi}$(p, pxn)${}^{207,206,205,204,203}\mathrm{Bi}$ reactions were measured using the stacked-foil technique. In our previous work, excitation functions of the mentioned reactions were measured at proton energies from 60 to 100 MeV. In this work, the excitation functions of the reactions are extended down to the proton energy of 40 MeV. Two targets were arranged in two different stacks including Bi, Al, and Au foils as well as Bi and Pb plates. After the irradiations, production yields of interested radionuclei were measured by $\gamma$-ray spectroscopy system using HPGe detectors. Proton beam intensities were measured using ${}^{27}\mathrm{Al}$($p, 3pn$)${}^{24}\mathrm{Na}, {}^{197}\mathrm{Au}$($p, p3n$)${}^{194}\mathrm{Au}$, and ${}^{197}\mathrm{Au}$($p, pn$)${}^{196}\mathrm{Au}$ monitor reactions. More than 50 cross-section data points were measured, including independent and cumulative cross sections. A similar trend was found between the data measured in this work and our earlier work. Our measured data were consistent with the experimental data in the literature. Excitation functions of the investigated reactions were also calculated using the talys-1.9 code with six different level density models. The results showed that phenomenological level density models predicted higher cross-section value than the microscopic level density models for the ${}^{209}\mathrm{Bi}$(p, xn) reactions. However, microscopic level density models indicated higher calculated cross sections for the ${}^{209}\mathrm{Bi}$(p, pxn) reactions.

Hadronic resonances, having very short lifetimes, like ${\mathrm{K}}^{*0}$, can act as useful probes to understand and estimate the lifetimes of hadronic phases in ultrarelativistic proton-proton, $p$-Pb, and heavy-ion collisions. Resonances with relatively longer lifetime, like $\varphi$ mesons, can serve as tools to locate the quark-gluon plasma (QGP) phase boundary. We estimate a lower limit of hadronic phase lifetime in Cu-Cu and Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) and in $pp, p$-Pb, and Pb-Pb collisions at different Large Hadron Collider (LHC) collision energies. Also, we obtain the effective temperature of $\varphi$ mesons using the Boltzmann-Gibbs blast-wave function, which gives insight into locating the QGP phase boundary. We observe that the hadronic phase lifetime strongly depends on final-state charged-particle multiplicity, whereas the QGP phase and hence the QCD phase boundary shows very weak multiplicity dependence. This suggests that the hadronization from a QGP state starts at a similar temperature irrespective of charged-particle multiplicity, collision system, and collision energy, while the endurance of hadronic phase is strongly dependent on final-state charged-particle multiplicity, system size, and collision energy.

We study the fluctuations of net charge, net pion, net kaon, and net proton using the ${\nu }_{\text{dyn}}$ variable in the heavy-ion jet interaction generator (HIJING), ultrarelativistic quantum molecular dynamics (UrQMD), and hadron resonance gas (HRG) model at different collision energies $\sqrt{s_{{}_{NN}}}$. It has been observed that the values of ${\nu }_{\text{dyn}}$ strongly depend on $\mathrm{\Delta }\eta$ in the HIJING and UrQMD models and are independent in the HRG model. The present work emphasizes the particle species dependence of net charge fluctuation strength and provides a baseline for comparison with the experimental data.

A new interpretation for the wobbling bands in the even-odd Lu isotopes is given within a particle-triaxial rotor semiclassical formalism. While in the previous papers the bands TSD1, TSD2, TSD3, and TSD4 are viewed as the ground, one, two, and three phonon wobbling bands, respectively, here the corresponding experimental results are described as the ground band with spin equal to $I=R+j$, for $R=0,2,4,...$ (TSD1), the ground band with $I=R+j$ and $R=1,3,5,...$ (TSD2), the one phonon excitations of TSD2 (TSD3), with the odd proton moving in the orbit $j=i_{13/2}$, and the ground band of $I=R+j$, with $R=1,3,5,...$ and $j=h_{9/2}$ (TSD4). The moments of inertia (MoI) of the core for the first three bands are the same, and considered to be free parameters. Due to the core polarization effect caused by the particle-core coupling, the MoI's for TSD4 are different. The energies and the electromagnetic transitions are quantitatively well described. Also, the phase diagram of the odd system is drawn. In the parameter space, one indicates where the points associated with the fitted parameters are located, which is the region where the transversal wobbling mode might be possible, as well as where the wobbling motion is forbidden.

Properties of fission in ${}^{233}\mathrm{U}$ were measured at the Los Alamos Neutron Science Center at incident neutron energies from thermal to 40 MeV. Fragments were observed in coincidence by using a twin ionization chamber with Frisch grids. The average total kinetic energy released and fragment mass yields were determined by using the double energy analysis method based on conservation of mass and momentum. The experimental method was validated by using ${}^{232}\mathrm{Th}$ and absolute energy was calibrated by using thermal-neutron–induced fission of ${}^{235}\mathrm{U}$. This work incorporates novel applications of multi-chance fission channel cross sections and fission models to account for the complexities introduced by prompt neutron emission at high energy and extends results up to higher incident neutron energies than previously measured. Accurate experimental measurements of these parameters are necessary to better understand the fission process in isotopes central to the thorium fuel cycle.

The generalized liquid drop model (GLDM) is first extended to study the two-proton $\left(2p\right)$ radioactivity half-lives of the ground state of nuclei. According to the comparison between the calculated half-lives and the experimental data, it is shown that the GLDM describes the $2p$ radioactivity half-lives well. In addition, by comparing its accuracy with other models, it is found that the GLDM has a comparable accuracy with them. Finally, the $2p$ radioactivity half-lives of some of the most probable candidates are predicted with the GLDM by inputting the $Q_{2p}$ values (the released energy of the $2p$ radioactivity) from the updated 2016 Atomic Mass Evaluation mass table, which may be useful for future experiments.