Photoneutron cross sections were measured for five stable Nd isotopes, ${}^{143,144,145,146,148}\mathrm{Nd}$, near neutron threshold with highly monochromatic laser-Compton scattering $\gamma$ rays. The photoneutron data were compared with the calculations performed with the talys reaction code with inputs of the Skyrme Hartree-Fock-Bogoliubov (HFB) plus quasi-particle random phase approximation (QRPA) model and the axially symmetric deformed Gogny HFB plus QRPA model of $E1$ $\gamma$-ray strength. Using the $\gamma$-ray strength function constrained by the present photoneutron data, a thorough analysis of the reverse $(n,\gamma )$ cross sections is made. Radiative neutron capture cross sections for an s-process branching-point nucleus in the rare earth region, ${}^{147}\mathrm{Nd}$ with the half-life 10.98 d, are deduced with the $\gamma$-ray strength function method. The impact of the newly evaluated ${}^{147}\text{Nd}{(n,\gamma )}^{148}\text{Nd}$ cross section on s-process nucleosynthesis is discussed.

To solve difficulties related to the use of nuclear density functional theory applied in its beyond-mean-field version, we introduce a semicontact three-body effective interaction. We show that this interaction is a good candidate to replace the widely used density-dependent effective interaction. The resulting new functionals are able to describe symmetric, neutron, polarized, and neutron polarized nuclear matter as well as the effective mass properties simultaneously.

We reanalyze $2\alpha +t$ cluster features of $3/2^{-}$ states in ${}^{11}\mathrm{B}$ by investigating the $t$-cluster distribution around a $2\alpha$ core in ${}^{11}\mathrm{B}$, calculated with the method of antisymmetrized molecular dynamics. In the $3/2_3^{-}$ state, a $t$ cluster is distributed in a wide region around $2\alpha$, indicating that the $t$ cluster moves rather freely in angular as well as radial motion. From the weak angular correlation and radial extent of the $t$-cluster distribution, we propose an interpretation of a $2\alpha +t$ cluster gas for the $3/2_3^{-}$ state. In this study, we compare the $2\alpha +t$ cluster feature in ${}^{11}\mathrm{B}(3/2_3^{-}$) with the $3\alpha$ cluster feature in ${}^{12}\mathrm{C}(0_2^{+}$) and discuss their similarities and differences.

The issue of the existence of reflection asymmetry in ${}^{145}\mathrm{Ba}$ has stood for the past 30 years without a common conclusion. The recent experimental data show a number of low-lying rotational bands with alternative parities, providing more strict constraints on the relevant modeling. With a proper octupole deformation, all the observed six rotational bands in ${}^{145}\mathrm{Ba}$ have been well reproduced by the reflection asymmetric shell model (RASM). The three octupole deformed neutron single-particle orbitals just above the octupole shell gap 88, with $K=1/2,K=3/2$, and $K=5/2$, respectively, dominate the intrinsic configurations of the observed bands. Based on the analysis of the calculated RASM wave functions, the assignments for the observed bands have been given. The experimental yrast band ($\Delta I=1$) presents a simplex inversion at around the $11/2^{-}$ state where the simplex staggering phase changes. This phenomenon may be explained in the framework of the RASM as from the change of the dominate intrinsic configuration, induced by the band mixing. The present results strongly support the appearance of the reflection asymmetry in the ground and low-lying states of ${}^{145}\mathrm{Ba}$.

Negative parity high-spin states of ${}^{107}\mathrm{Cd}$ have been investigated using the reaction ${}^{94}\mathrm{Zr}({}^{18}\mathrm{O}$,5n), from the $\gamma$-ray coincidence events recorded by the Indian National Gamma Array. A magnetic dipole ($M1$) band structure was established for the first time in this nucleus decaying to the low-spin states via several paths. Lifetimes of five in-band levels in this band have been measured using the Doppler shift attenuation method. The experimentally deduced $B\left(M1\right)$ values are found to decrease with increasing spin. The experimental observations, interpreted by the tilted axis cranking calculations, suggest that the $M1$ band is developed from the shears mechanism based on the 5qp configuration $\pi \left(g_{9/2}^{-2}\right)\otimes \nu \left(h_{11/2}{g}_{7/2}^2\right)$, which is then crossed by another 5qp configuration $\pi \left(g_{9/2}^{-2}\right)\otimes \nu \left(h_{11/2}^3\right)$. The semiclassical model of the shears mechanism also reasonably reproduces the decreasing trend of the observed $B\left(M1\right)$ values as a function of spin, supporting the above interpretation. The present work highlights the unique coexistence of both magnetic and antimagnetic (observed by us earlier) rotation bands in one nucleus arising from the same proton configuration, but different neutron configurations.

Lifetimes of low-lying excited states have been measured in ${}^{66}\mathrm{Ge},{}^{69}\mathrm{Se}$, and ${}^{65}\mathrm{Ga}$ using a $\gamma$-ray lineshape method. The results confirm the previously reported $7_1^{-}$ state lifetime in ${}^{66}\mathrm{Ge}$. The lifetime of the yrast $5/2^{-}$ state in ${}^{65}\mathrm{Ga}$ is measured for the first time. Lifetime measurements of two excited $3/2^{-}$ states in ${}^{69}\mathrm{Se}$ are also reported. Two previously unobserved $\gamma$ rays have been identified in ${}^{69}\mathrm{Se}$. $\gamma -\gamma$ coincidence measurements have been used to place one of these in the level scheme. ${}^{69}\mathrm{Se}$ excited state populations are compared to shell-model calculations using the GXPF1A interaction in the $\mathit{fp}$ model space. Theoretical spectroscopic factors to excited states in ${}^{69}\mathrm{Se}$ have identified three candidate levels for the origin of one of the new transitions.

Background: In heavy-ion collisions at intermediate energies the production of light charged particles and intermediate mass fragments (IMFs) is due to different reaction mechanisms and different time scales, ranging from fast dynamical processes to statistical emission from the equilibrated system.

Purpose: We compare the IMF statistical and dynamical emission probabilities in collisions of a neutron-rich ${}^{124}\mathrm{Sn}+{}^{64}\mathrm{Ni}$ system and a neutron-poor ${}^{112}\mathrm{Sn}+{}^{58}\mathrm{Ni}$ system at the laboratory energy of 35 $A$ MeV.

Method: The IMFs production mechanism in semiperipheral reactions has been investigated in our previous works. In this paper, the analysis is expanded for the same set of data and production cross sections have been evaluated for dynamical and statistical emission in a coherent way for light and heavy fragments.

Results: The data analysis has evidenced a strong competition between dynamical and statistical emission mechanisms. Probability of the dynamical emission of IMFs is strongly influenced by the ($N/Z$) ratio of the colliding system.

Conclusions: It is demonstrated that the statistical emission is equally probable for the two systems, while the dynamical emission is enhanced for the neutron-rich system, especially for heavy fragments ($Z\ge 6$). The observed effect points at a high sensitivity of the prompt-dynamical emission to the ($N/Z$) ratio of a given system.

Thermal properties of asymmetric nuclear matter, including the temperature dependence of the symmetry energy, single-particle properties, and differential isospin fractionation, are investigated with different neutron-proton effective mass splittings by using an improved isospin- and momentum-dependent interaction. In this improved interaction, the momentum dependence of the isoscalar single-particle potential at saturation density is well fit to that extracted from optical-model analyses of proton-nucleus scattering data up to the nucleon kinetic energy of 1 GeV, and the isovector properties, i.e., the slope of the nuclear symmetry energy, the momentum dependence of the symmetry potential, and the symmetry energy at saturation density, can be flexibly adjusted via three parameters: $x,y$, and $z$, respectively. Our results indicate that the nucleon phase-space distribution in equilibrium, the temperature dependence of the symmetry energy, and the differential isospin fractionation can be significantly affected by the isospin splitting of the nucleon effective mass.

The energy dependence of particle production sources in relativistic heavy-ion collisions is investigated from RHIC (Relativistic Heavy Ion Collider) to LHC (Large Hadron Collider) energies. Whereas charged-hadron production in the fragmentation sources follows a $ln(s_{NN}/s_0)$ law, particle production in the mid-rapidity gluon-gluon source exhibits a much stronger dependence $\propto {ln}^3(s_{NN}/s_0)$, and becomes dominant between RHIC and LHC energies. The production of particles with pseudorapidities beyond the beam rapidity is also discussed.

A key ingredient of hydrodynamical modeling of relativistic heavy ion collisions is thermal initial conditions, an input that is the consequence of a prethermal dynamics which is not completely understood yet. In the paper we employ a recently developed energy-momentum transport model of the prethermal stage to study influence of the alternative initial states in nucleus-nucleus collisions on flow and energy density distributions of the matter at the starting time of hydrodynamics. In particular, the dependence of the results on isotropic and anisotropic initial states is analyzed. It is found that at the thermalization time the transverse flow is larger and the maximal energy density is higher for the longitudinally squeezed initial momentum distributions. The results are also sensitive to the relaxation time parameter, equation of state at the thermalization time, and transverse profile of initial energy density distribution: Gaussian approximation, Glauber Monte Carlo profiles, etc. Also, test results ensure that the numerical code based on the energy-momentum transport model is capable of providing both averaged and fluctuating initial conditions for the hydrodynamic simulations of relativistic nuclear collisions.

I investigate the neutron number $\left(N\right)$ dependence of root-mean-square radii of point proton distribution (proton radii) of Be, B, and C isotopes with the theoretical method of variation after spin-parity projection in the framework of antisymmetrized molecular dynamics (AMD). The proton radii in Be and B isotopes changes rapidly as $N$ increases, reflecting the cluster structure change along the isotope chains, whereas those in C isotopes show a weak $N$ dependence because of the stable proton structure in nuclei with $Z=6$. In neutron-rich Be and B isotopes, the proton radii are remarkably increased by the enhancement of the two-center cluster structure in the prolately deformed neutron structure. I compare the $N$ dependence of the calculated proton radii with the experimental ones reduced from the charge radii determined by isotope shift and those deduced from the charge changing interaction cross section. It is found that the $N$ dependence of proton radii can be a probe to clarify enhancement and weakening of cluster structures.

We investigate the elliptic and the triangular flow of heavy mesons in ultrarelativistic heavy-ion collisions at the BNL Relativistic Heavy-Ion Collider and the CERN Large Hadron Collider (LHC) . The dynamics of heavy quarks is coupled to the locally thermalized and fluid dynamically evolving quark-gluon plasma. The elliptic flow of $D$ mesons and the centrality dependence measured at the LHC is well reproduced for purely collisional and bremsstrahlung interactions. Due to the event-by-event fluctuating initial conditions from the EPOS2 model, the $D$ meson triangular flow is predicted to be nonzero at $\sqrt{s}=200$ GeV and $\sqrt{s}=2.76$ TeV. We study the centrality dependence and quantify the contributions stemming from flow of the light bulk event and the hadronization process. The flow coefficients as responses to the initial eccentricities behave differently for heavy mesons than for light hadrons due to their inertia. Higher-order flow coefficients of heavy flavor become important in order to quantify the degree of thermalization.

On the basis of the Brueckner-Hartree-Fock method with the nucleon-nucleon forces obtained from lattice QCD simulations, the properties of the medium-heavy doubly magic nuclei such as ${}^{16}\mathrm{O}$ and ${}^{40}\mathrm{Ca}$ are investigated. We found that those nuclei are bound for the pseudoscalar meson mass $M_{\mathrm{PS}}\simeq 470$ MeV. The mass number dependence of the binding energies, single-particle spectra, and density distributions are qualitatively consistent with those expected from empirical data at the physical point, although these hypothetical nuclei at heavy quark mass have smaller binding energies than the real nuclei.

Background: A recent survey of well-deformed rare earth nuclei showed that $B\left(E2\right)$ values from the $\gamma$ band to the ground band could be explained rather well by a parameter-free description in terms of a partial dynamical symmetry (PDS).

Purpose: Our purpose here is to extend this study to deformed and transitional nuclei in the actinide and $\mathrm{A}\sim 100$ regions to determine if the success of the PDS description is general in medium- and heavy-mass nuclei and to investigate further where it breaks down.

Method: As with the previous study we study the empirical relative $B$($E2:\gamma$ to ground) values in comparison to a pure rotor (Alaga) model and to the SU(3) PDS.

Results: The data for the actinides, albeit sparser than in the rare-earth region, are reasonably well accounted for by the PDS but with systematic discrepancies. For the Mo isotopes, the PDS improves on the Alaga rules but largely fails to account for the data.

Conclusions: As in the rare earths, the parameter-free PDS gives improved predictions compared to the Alaga rules for the actinides. The differences between the PDS predictions and the data are shown to point directly to specific mixing effects. In the Mo isotopes, their transitional character is directly seen in the large deviations of the $B\left(E2\right)$ values from the PDS in the direction of the selection rules of the vibrator.

The nonlocalized aspect of clustering, which is a new concept for self-conjugate nuclei, is extended for the investigation of the $N\ne Z$ nucleus ${}^9\mathrm{Be}$. A modified version of the Tohsaki-Horiuchi-Schuck-Röpke (THSR) wave function is introduced with a new phase factor. It is found that the constructed negative-parity THSR wave function is very suitable for describing the cluster states of ${}^9\mathrm{Be}$. Namely, the nonlocalized clustering is shown to prevail in ${}^9\mathrm{Be}$. The calculated binding energy and radius of ${}^9\mathrm{Be}$ are consistent with calculations in other models and with experimental values. The squared overlaps between the single THSR wave function and the Brink + generator coordinate method wave function for the $3/2^{-}$ rotational band of ${}^9\mathrm{Be}$ are found to be near 96%. Furthermore, by showing the density distribution of the ground state of ${}^9\mathrm{Be}$, the $\pi$-orbit structure is naturally reproduced by using this THSR wave function.

We study the spectrum of ${}_{\Lambda }^{12}\mathrm{Be}$ by using an extended version of antisymmetrized molecular dynamics for hypernuclei. Our result indicates that the $\Lambda$-particle impurity effect causes the positive-parity ground state of ${}_{\Lambda }^{12}\mathrm{Be}$ to revert to the normal state, i.e., negative parity. This parity reversion is attributed to the difference in the $\Lambda$ binding energy between the positive- and negative-parity states, which in turn originates in the difference in $\alpha$ clustering and deformation.

We use symmetry arguments developed by Gubser to construct the first radially expanding explicit solutions of the Israel-Stewart formulation of hydrodynamics. Along with a general semi-analytical solution, an exact analytical solution is given which is valid in the cold plasma limit where viscous effects from shear viscosity and the relaxation time coefficient are important. The radially expanding solutions presented in this paper can be used as nontrivial checks of numerical algorithms employed in hydrodynamic simulations of the quark-gluon plasma formed in ultrarelativistic heavy ion collisions. We show this explicitly by comparing such analytic and semi-analytic solutions with the corresponding numerical solutions obtained using the music viscous hydrodynamics simulation code.

In the mean field approximation, the derivative of the grand potential, nonstrange and strange condensates, and the deconfinement phase transition in a thermal and dense hadronic medium are verified in the SU(3) Polyakov linear-$\sigma$ model (PLSM). The chiral condensates ${\sigma }_x$ and ${\sigma }_y$ are analyzed with the goal of determining the chiral phase transition. The temperature and density dependences of the chiral mesonic phase structures are taken as free parameters and fitted experimentally. They are classified according to the scalar meson nonets: (pseudo)scalar and (axial) vector. For the deconfinement phase transition, the effective Polyakov-loop potentials $\varphi$ and ${\varphi }^{*}$ are implemented. The in-medium effects on the masses of sixteen mesonic states are investigated. The results are presented for two different forms for the effective Polyakov-loop potential and compared with other models, which include and exclude the anomalous terms. It is found that the Polyakov-loop potential has considerable effects on the chiral phase transition so that the restoration of the chiral symmetry breaking becomes sharper and faster. Assuming that the Matsubara frequencies contribute to the meson masses, we have normalized all mesonic states with respect to the lowest frequency. By doing this, we characterize temperatures and chemical potentials at which the different meson states dissolve to free quarks. Different dissolving temperatures and chemical potentials are estimated. The different meson states survive the typically averaged QCD phase boundary, which is defined by the QCD critical temperatures at varying chemical potentials. The thermal behavior of all meson masses has been investigated in the large-$N_c$ limit. It is found that, at high $T$, the scalar meson masses are $T$ independent (except $\pi$ and $\sigma )$. For the pseudoscalar meson masses, the large-$N_c$ limit unifies the $T$ dependences of the various states into a universal bundle. The same is also observed for axial and axial-vector meson masses.