Because the relatively small neutron capture cross sections of the zirconium isotopes are difficult to measure, the results of previous measurements are often not adequate for a number of problems in astrophysics and nuclear technology. Therefore, the ${}^{92}\mathrm{Zr}$($n,\gamma$) cross section has been remeasured at the CERN n_TOF facility, providing a set of improved parameters for 44 resonances in the neutron energy range up to 40 keV. With this information the cross-section uncertainties in the keV region could be reduced to $5\%$ as required for $s$-process nucleosynthesis studies and technological applications.

We calculate the elliptic flow parameter $v_2$ for $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV employing the parton cascade Boltzmann approach of multiparton scatterings. Besides gluon interactions including the bremsstrahlung process, interactions with quarks are considered in an effective, but approximate, way to investigate the dependence of the collective flow on the number of parton degrees of freedom. We find that $v_2$ as a function of the transverse momentum $p_T$ is sensitive to the number of parton degrees of freedom, whereas the $p_T$-averaged $v_2$ does not. When including quarks, $v_2(p_T)$ shifts to lower $p_T$, the parton transverse momentum spectra become softer, and the mean parton transverse momenta decrease.

Time-dependent density-matrix propagation is used to demonstrate, in a schematic model of an open quantum system, that the complex potential approach and the Lindblad dissipative dynamics are not equivalent. While the former preserves coherence, it is destroyed in the Lindblad dissipative dynamics. Quantum decoherence is the key aspect that makes the difference between the two approaches, indicating that the complex potential model is inadequate for a consistent description of open quantum-system dynamics. It is suggested that quantum decoherence should always be explicitly included when modeling low-energy nuclear collision dynamics within a truncated model space of reaction channels.

The semiclassical Wigner-Kirkwood $\hslash$ expansion method is used to calculate shell corrections for spherical and deformed nuclei. The expansion is carried out up to fourth order in $\hslash$. A systematic study of Wigner-Kirkwood averaged energies is presented as a function of the deformation degrees of freedom. The shell corrections, along with the pairing energies obtained by using the Lipkin-Nogami scheme, are used in the microscopic-macroscopic approach to calculate binding energies. The macroscopic part is obtained from a liquid drop formula with six adjustable parameters. Considering a set of 367 spherical nuclei, the liquid drop parameters are adjusted to reproduce the experimental binding energies, which yields a root mean square (rms) deviation of 630 keV. It is shown that the proposed approach is indeed promising for the prediction of nuclear masses.

We propose a semiempirical nuclear mass formula based on the macroscopic-microscopic method in which the isospin and mass dependence of model parameters are investigated with the Skyrme energy density functional. The number of model parameters is considerably reduced compared with the finite range droplet model. The rms deviation with respect to 2149 measured nuclear masses is reduced by 21%, falling to 0.516 MeV. The new magic number $N=16$ in light neutron-rich nuclei and the shape coexistence phenomena for some nuclei have been examined with the model. The shell corrections of superheavy nuclei are also predicted.

We propose a few selected experimental approaches to show that new-generation instruments can give a direct access to significant observables on the density dependence of the symmetry energy in the nuclear equation of state. The form of such dependence is investigated within the stochastic mean field model, coupled to a secondary-decay treatment.

The relative isobaric yields of fragments produced in a series of heavy-ion-induced multifragmentation reactions have been analyzed in the framework of a modified Fisher model, primarily to determine the ratio of the symmetry energy coefficient to the temperature, $a_{\mathrm{sym}}/T$, as a function of fragment mass $A$. The extracted values increase from 5 to $~$16 as $A$ increases from 9 to 37. These values have been compared to the results of calculations using the antisymmetrized molecular dynamics (AMD) model together with the statistical decay code gemini. The calculated ratios are in good agreement with those extracted from the experiment. In contrast, the values extracted from the ratios of the primary isobars from the AMD model calculation are $~$4 to 5 and show little variation with $A$. This observation indicates that the value of the symmetry energy coefficient derived from final fragment observables may be significantly different than the actual value at the time of fragment formation. The experimentally observed pairing effect is also studied within the same simulations. The Coulomb coefficient is also discussed.

We have studied the centrality dependence of charged-particle forward-backward multiplicity correlation strength in Au$+$Au collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV with a parton and hadron cascade model, PACIAE, based on PYTHIA. The calculated results are compared with the STAR data. The experimentally observed correlation strength characteristics, ($1$) the approximately flat pseudorapidity dependence in central collisions and ($2$) the monotonous decrease with decreasing centrality, are reproduced well. However, the theoretical results are larger than the STAR data for the peripheral collisions. We compare the different models and STAR data. A prediction for the forward-backward multiplicity correlation in Pb$+$Pb collisions at $\sqrt{s_{\mathit{NN}}}=5500$ GeV is also given.

Elastic electromagnetic form factors of nucleons are investigated for both the time-like and the space-like momenta by using the unsubtracted dispersion relation with QCD constraints. It is shown that the calculated form factors reproduce the experimental data reasonably well; they agree with recent experimental data for the neutron magnetic form factors for the space-like data obtained by the CLAS Collaboration and are compatible with the ratio of the electric and magnetic form factors for the time-like momentum obtained by the BABAR Collaboration.

The unquenched quark models predict the new particle ${\Sigma }^{*}$ with spin-parity $J^P=1/2^{-}$ and its mass is around the well-established ${\Sigma }^{*}(1385)$ with $J^P=3/2^{+}$. Here, by using the effective Lagrangian approach, we study $K^{-}p\to \Lambda {\pi }^{-}{\pi }^{+}$ reaction at the range of ${\Lambda }^{*}(1520)$ peak, comparing the resulting total cross section, and ${\pi }^{+}{\pi }^{-}$, $\Lambda {\pi }^{+}$, $\Lambda {\pi }^{-}$ invariant squared mass distributions for various incident $K^{-}$ momenta, as well as the production angular distribution of the $\Lambda$ with the data from the Lawrence Berkeley Laboratory $25$-inch hydrogen bubble chamber; we find that, apart from the existing resonance ${\Sigma }^{*}(1385)$ with $J^P=3/2^{+}$, there is evidence for possible existence of the new resonance ${\Sigma }^{*}$ with $J^P=1/2^{-}$ around $1380$ MeV. Higher statistic data on relevant reactions are needed to clarify the situation.

Dependence of nuclear level density parameter on the angular momentum and temperature is investigated in a theoretical framework using the statistical theory of hot rotating nuclei. The structural effects are incorporated by including shell correction, shape, and deformation. The nuclei around $Z\approx 50$ with an excitation energy range of $30$ to $40$ MeV are considered. The calculations are in good agreement with the experimentally deduced inverse level density parameter values especially for ${}^{109}\mathrm{In}$, ${}^{113}\mathrm{Sb}$, ${}^{122}\mathrm{Te}$, ${}^{123}\mathrm{I}$, and ${}^{127}\mathrm{Cs}$ nuclei.

Penning trap mass spectrometry is presented as a complementary tool to nuclear spectroscopy experiments for the study of nuclear structure in the vicinity of $N=40$, $Z=28$. High-precision mass measurements of the ${}^{63-66}\mathrm{Fe}$ and ${}^{64-67}\mathrm{Co}$ isotopes have been carried out with the Low Energy Beam and Ion Trap (LEBIT) Penning trap mass spectrometer. The newly obtained mass values for ${}^{66}\mathrm{Fe}$ and ${}^{67}\mathrm{Co}$ are presented, together with the previously reported LEBIT mass measurements in this region. In the case of ${}^{65}\mathrm{Fe}$ the existence of a new isomer is reported, and an isomer recently discovered by decay spectroscopy in ${}^{67}\mathrm{Co}$ is confirmed. Relative mass uncertainties as low as $4\times {10}^{-8}$ are obtained. All mass values are found to be in good agreement with previous experimental results with the exception of ${}^{64}\mathrm{Co}$, where a $5\sigma$ deviation is observed. Using these data the two neutron separation energies $S_{2n}$ are calculated. However, the large error bars in the mass values of the neighbor Fe and Co isotopes with $N>40$ complicate the validation of a weak subshell closure at $N=40$ for the Co isotopes or the possible reduction in the neutron shell gap in the case of the Fe isotopes, in accordance with the theoretical predictions of an onset of deformation in the region.

The nucleon effective interaction is calculated in the framework of the Dirac-Brueckner-Hartree-Fock approach, which has been illustrated to reproduce well the ground-state properties and the experimental data of proton and $\alpha$ particle scattering off nuclei. The nuclear potential of the $\alpha$–nucleus is obtained by doubly folding the nucleon effective interaction with respect to the density distributions of both the $\alpha$ particle and daughter nucleus. We apply this new nuclear potential of the $\alpha$–nucleus to investigate the $\alpha$-decay half-lives of superheavy elements in the preformed cluster model along with the experimental decay energies $Q_{\exp }$. Good agreement with the experimental data is achieved. We also systematically calculate the $\alpha$-decay half-lives for 19 isotope chains ($Z=102–120$) in this framework using the theoretical $\alpha$-decay energies $Q_{\mathrm{th}}$ extracted from the Möller-Nix-Kratz mass table. The predicted results are compared with those obtained by using the same $Q_{\mathrm{th}}$ but the nuclear potentials evaluated with M3Y effective interaction and also with the results calculated in the empirical formulas of the Viola-Seaberg-Sobiczewski formula.

The higher Tamm-Dancoff Approximation (HTDA) is extended to include vibrational correlations with or without pairing correlations. The residual interaction in use is of the delta (in the $T=1$ channel) plus multipole-multipole type. In this paper we have limited our study to the mere case of isoscalar quadrupole correlations. The approach is illustrated by the consideration of ground state and isoscalar giant quadrupole resonance properties in the ${}^{40}\mathrm{Ca}$ nucleus.

We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.

Analytical solution of a one-dimensional hydrodynamical model is derived, where phase transition from the quark-gluon plasma state to the hadronic state is effectively taken into account. The single-particle rapidity distribution of charged $\pi$ mesons observed in relativistic heavy ion collisions is analyzed by the model. Space-time development of the fluid is also investigated.

The effects of nonzero baryonic chemical potential on the drag and diffusion coefficients of heavy quarks propagating through a baryon-rich quark-gluon plasma have been studied. The nuclear suppression factor $R_{\mathit{AA}}$ for nonphotonic single-electron spectra resulting from the semileptonic decays of hadrons containing heavy flavors has been evaluated for low-energy collisions. The effect of nonzero baryonic chemical potential on $R_{\mathit{AA}}$ is highlighted.

We investigate the influence of a deconfinement phase transition on the dynamics of hot and dense nuclear matter. To this aim a hybrid model with an intermediate hydrodynamic stage for the hot and dense phase of the system is employed for collisions of $\mathrm{Pb}+\mathrm{Pb}/\mathrm{Au}+\mathrm{Au}$ at beam energies of $E_{\mathrm{lab}}=2$–160 A GeV, while initial and final interactions are performed by a microscopic transport approach (UrQMD). In the hydrodynamic stage an equation of state that incorporates a critical end point in line with lattice data is used. It follows from coupling the Polyakov loop (as an order parameter for deconfinement) to a chiral hadronic $\mathit{SU}(3){}_f$ model. In this configuration the equation of state describes chiral restoration as well as the deconfinement phase transition. We compare the results from this new equation of state to results obtained, by applying a hadron resonance gas equation of state, focusing on bulk observables deemed to be sensitive to the phase transition to a quark-gluon plasma.

Effective energy windows (Gamow windows) of astrophysical reaction rates for ($p,\gamma$), ($p,n$), ($p,\alpha$), ($\alpha ,\gamma$), ($\alpha ,n$), ($\alpha ,p$), ($n,\gamma$), ($n,p$), and ($n,\alpha$) on targets with $10⩽Z⩽83$ from proton to neutron dripline are calculated using theoretical cross sections. It is shown that widely used approximation formulas for the relevant energy ranges are not valid for a large number of reactions relevant to hydrostatic and explosive nucleosynthesis. The influence of the energy dependence of the averaged widths on the location of the Gamow windows is discussed and the results are presented in tabular form.

The lowest-energy resonance in the ${}^{23}\mathrm{Mg}$($p,\gamma$)${}^{24}\mathrm{Al}$ reaction, which is dominant at classical nova temperatures, has been measured directly for the first time using the DRAGON recoil spectrometer. The experiment used a radioactive ${}^{23}\mathrm{Mg}$ beam (mixed within a significantly stronger ${}^{23}\mathrm{Na}$ beam) of peak intensity $5\times {10}^7$ $\mathrm{s}{}^{-1}$, at the ISAC facility at TRIUMF. We extract values of $E_R={485.7}_{-1.8}^{+1.3}$ keV and $\omega \gamma ={38}_{-15}^{+21}$ meV from our data (all values in the center-of-mass frame unless otherwise stated). In addition, the experiment prompted a recalculation of the $Q$ value for this reaction based on a revision of the ${}^{24}\mathrm{Al}$ mass. The effect on the uncertainties in the quantities of ejected ${}^{22}\mathrm{Na}$ and ${}^{26}\mathrm{Al}$ from oxygen-neon classical novae is discussed.