Using various relativistic mean-field models, including nonlinear ones with meson field self-interactions, models with density-dependent meson-nucleon couplings, and point-coupling models without meson fields, we have studied the isospin-dependent bulk and single-particle properties of asymmetric nuclear matter. In particular, we have determined the density dependence of nuclear symmetry energy from these different relativistic mean-field models and compared the results with the constraints recently extracted from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions as well as from measured isotopic dependence of the giant monopole resonances in even-$A$ Sn isotopes. Among the 23 parameter sets in the relativistic mean-field model that are commonly used for nuclear structure studies, only a few are found to give symmetry energies that are consistent with the empirical constraints. We have also studied the nuclear symmetry potential and the isospin splitting of the nucleon effective mass in isospin asymmetric nuclear matter. We find that both the momentum dependence of the nuclear symmetry potential at fixed baryon density and the isospin splitting of the nucleon effective mass in neutron-rich nuclear matter depend not only on the nuclear interactions but also on the definition of the nucleon optical potential.

Elastic scattering of 240 MeV ${}^6\mathrm{Li}$ ions from ${}^{116}\mathrm{Sn}$ was measured from $4^{°}⩽{\theta }_{\mathrm{c}.\mathrm{m}.}⩽{32}^{°}$. The data were fitted with a Woods-Saxon phenomenological potential and with double folding models using the $M3Y$ $\mathit{NN}$ effective interaction with and without density dependence. DWBA calculations with the fitted parameters were used to calculate cross sections for inelastic scattering to low-lying $2^{+}$and $3^{-}$ states. $B(E2)$ and $B(E3)$ values were extracted and compared with electromagnetic values and those obtained from $\alpha$ inelastic scattering.

We have calculated the $p\text{−}$${}^{4,6,8}\mathrm{He}$ elastic scattering differential cross section and polarizations at 297 MeV using the Multiple Scattering expansion of the Optical potential (MSO) reaction scattering framework. The role of the core and valence neutrons contribution to the interaction in the description of the elastic scattering observables is analyzed.

We propose a way of detecting $\mathit{CP}$ violation in a single neutrino oscillation channel at very long baselines (on the order of several thousands of kilometers), given precise knowledge of the smallest mass-squared difference. It is shown that $\mathit{CP}$ violation can be characterized by a shift in $L/E$ of the peak oscillation in the ${\nu }_e\text{−}{\nu }_{\mu }$ appearance channel, both in vacuum and in matter. In fact, matter effects enhance the shift at a fixed energy. We consider the case in which sub-GeV neutrinos are measured with varying baseline and also the case of a fixed baseline. For the varied baseline, accurate knowledge of the absolute neutrino flux would not be necessary; however, neutrinos must be distinguishable from antineutrinos. For the fixed baseline, it is shown that $\mathit{CP}$ violation can be distinguished if the mixing angle ${\theta }_{13}$ were known.

In the framework of the density functional theory for superconductors, we study the restoration of the particle-number symmetry by means of the projection technique. Conceptual problems are outlined and numerical difficulties are discussed. Both are related to the fact that neither the many-body Hamiltonian nor the wave function of the system appear explicitly in the density functional theory. Similar obstacles are encountered in self-consistent theories utilizing density-dependent effective interactions.

The capture cross sections and fission fragment angular distributions were measured for the reaction of ${}^{50}\mathrm{Ti}$ with ${}^{208}\mathrm{Pb}$ at center of mass projectile energies ($E_{\mathrm{c}.\mathrm{m}.}$) of 183.7, 186.2, 190.2, 194.2, and 202.3 MeV ($E^{*}=14.2$, 16.6, 20.6, 24.7, and 32.7 MeV). From fitting the backward angle fragment angular distributions, the cross sections for quasifission and fusion-fission and $P_{\mathrm{CN}}$, the probability that the colliding nuclei go from the contact configuration to inside the fission saddle point, were deduced. These quantities, along with the known values of the evaporation residue production cross sections for this reaction, were used to deduce values of the survival probabilities, $W_{\mathrm{sur}}$, for this reaction as a function of excitation energy. The deduced values of $P_{\mathrm{CN}}$ and $W_{\mathrm{sur}}$ and their dependence on excitation energy differ from some current theoretical predictions of these quantities.

An experiment was performed to study the ${}^9\mathrm{Be}$(${}^6\mathrm{Li}$,${}^6\mathrm{Li}$)${}^9\mathrm{Be}$${}^{*}$ $\to \alpha +\alpha +n$ reaction. This experiment was designed to study the breakup of ${}^9\mathrm{Be}$ in an attempt to quantify the breakup yield for each of the decay channels ($n+$ ${}^8\mathrm{Be}$ ${}^{\mathrm{g}.\mathrm{s}},n+$ ${}^8\mathrm{Be}$ ${}^{2^{+}}$, and $\alpha +$ ${}^5\mathrm{He}$ ${}^{\mathrm{g}.\mathrm{s}}$) from the low-lying states. The results suggest that the population of states in ${}^9\mathrm{Be}$ from 1.68 to 11.28 MeV can be identified. Branching ratios for each of the breakup channels have been estimated for these states. These results are compared with earlier experiments and with theoretical predictions. They confirm the theoretical claim that the $n+$ ${}^8\mathrm{Be}$ ${}^{2^{+}}$ and $\alpha +$ ${}^5\mathrm{He}$ ${}^{\mathrm{g}.\mathrm{s}}$ channels increase in importance at higher excitation energies.

We investigate the general relativistic (GR) effects on the conversion from nuclear to two-flavor quark matter in compact stars, both static as well as rotating. We find that GR effects lead to qualitative differences in rotating stars, indicating the inadequacy of nonrelativistic or even special relativistic treatments for these cases.

Enriched isotopic abundance ratios of ${}^{30}\mathrm{Si}$/${}^{28}\mathrm{Si}$ in several presolar SiC and graphite grains qualitatively indicate massive oxygen-neon (ONe) nova origins but fall short of hydrodynamic ONe nova model ejecta predictions by as much as an order of magnitude. The astrophysical ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ reaction rate uncertainty at ONe nova temperatures ($0.10<T<0.35$ GK) spans several orders of magnitude through which the predicted amount of ejected ${}^{30}\mathrm{Si}$ can vary by a factor of 100. By measuring triton momenta from the ${}^{31}\mathrm{P}$(${}^3\mathrm{He}$,$t$)${}^{31}\mathrm{S}$ reaction at 20 MeV, the energies of ${}^{30}\mathrm{P}$ $+p$ resonances in the Gamow window for ONe novae have been determined to better than ±3 keV, and two new resonances at $E_{\mathrm{c}.\mathrm{m}.}=194.0(25)$ and 266.4(27) keV that likely dominate the ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ rate for $0.08<T<0.25$ GK have been resolved. A resulting increase in the experimentally determined ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ reaction rate puts it in accord with Hauser-Feshbach statistical model estimates for $0.08<T<0.40$ GK, supporting conclusions drawn from ONe nova model studies that employed a Hauser-Feshbach rate.

Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear structure models. In addition to nuclear structure, GT transitions in nuclei directly affect the early phases of Type Ia and Type-II supernovae core collapse since the electron capture rates are partly determined by these GT transitions. In astrophysics, GT transitions provide an important input for model calculations and element formation during the explosive phase of a massive star at the end of its life-time. Recent nucleosynthesis calculations show that odd-odd and odd-$A$ nuclei cause the largest contribution in the rate of change of lepton-to-baryon ratio. In the present manuscript, we have calculated the GT strength distributions and electron capture rates for odd-odd nucleus ${}^{50}\mathrm{V}$ by using the pn-QRPA theory. At present ${}^{50}\mathrm{V}$ is the first experimentally available odd-odd nucleus in fp-shell nuclei. We also compare our GT strength distribution with the recently measured results of a ${}^{50}\mathrm{V}$($d$, ${}^2\mathrm{He}$)${}^{50}\mathrm{Ti}$ experiment, with the earlier work of Fuller, Fowler, and Newman (referred to as FFN) and subsequently with the large-scale shell model calculations. One curious finding of the paper is that the Brink's hypothesis, usually employed in large-scale shell model calculations, is not a good approximation to use at least in the case of ${}^{50}\mathrm{V}$. SNe Ia model calculations performed using FFN rates result in overproduction of ${}^{50}\mathrm{Ti}$, and were brought to a much acceptable value by employing shell model results. It might be interesting to study how the composition of the ejecta using presently reported QRPA rates compare with the observed abundances.

The β decay of the neutron-rich ${}_{30}^{81}{\mathrm{Zn}}_{51}$ has been investigated at the PARRNe mass separator at the IPN Orsay. The sources of ${}^{81}\mathrm{Zn}$ were produced using the ISOL (Isotopic Separation On Line) technique by the fission of ${}^{\mathrm{nat}}$U exposed to the neutron flux produced by the 26-MeV deuteron beam delivered by the MP-Tandem. With γ and $\gamma \text{−}\gamma$ coincidence measurements, excited levels were attributed to ${}_{31}^{81}{\mathrm{Ga}}_{50}$ for the first time. A partial decay scheme for ${}^{81}\mathrm{Zn}$ is proposed. The proposed level scheme is well reproduced by shell model calculations using the most recent effective empirical interaction. We show that the structure of this nucleus is consistent with that of the heavier odd-proton $N=50$ isotones within the assumption of strong proton $Z=28$ and neutron $N=50$ effective shell effects. The observed states can be associated to rather simple and clean configurations of three protons placed in the $1f_{5/2}$ and $2p_{3/2}$ orbits.

The question of the lifetime of the ${}^{229}{\mathrm{Th}}^m$ low-lying isomer is considered in light of current experimental research. A strong effect of the electron shell on lifetime is demonstrated, depending on the energy of the isomer. Calculations are performed within the framework of the multiconfiguration Dirac-Fock method. The calculated lifetime ranges from around 1 min down to ${10}^{-5}$ s. Prospects for further experimental research of the isomer are discussed.

We study several structure properties of finite nuclei using relativistic mean-field Lagrangians constructed according to the Brown-Rho scaling due to the chiral symmetry restoration at high densities. The models are consistent with current experimental constraints for the equations of state of symmetric matter at both normal and supranormal densities and of asymmetric matter at subsaturation densities. It is shown that these models can successfully describe the binding energies and charge radii of finite nuclei. Compared to calculations with usual relativistic mean-field models, these models give a reduced thickness of neutron skin in ${}^{208}\mathrm{Pb}$ between 0.17 fm and 0.21 fm. The reduction of the predicted neutron skin thickness is found to be due to not only the softening of the symmetry energy but also the scaling property of $\rho$ meson required by the partial restoration of chiral symmetry.

We investigate the average sizes of the $n$ largest fragments in nuclear multifragmentation events near the critical point of the nuclear matter phase diagram. We perform analytic calculations employing Poisson statistics as well as Monte Carlo simulations of the percolation type. We find that previous claims of manifestations of Zipf's Law in the rank-ordered fragment size distributions are not borne out in our result, in neither finite nor infinite systems. Instead, we find that Zipf-Mandelbrot distributions are needed to describe the results, and we show how one can derive them in the infinite size limit. However, we agree with previous authors that the investigation of rank-ordered fragment size distributions is an alternative way of looking for the critical point in the nuclear matter diagram.

We report on self-consistent calculations of single-$K^{-}$-nuclear states and multi-$\overline{K}$-nuclear states in ${}^{12}\mathrm{C}$, ${}^{16}\mathrm{O}$, ${}^{40}\mathrm{Ca}$, and ${}^{208}\mathrm{Pb}$ within the relativistic mean-field (RMF) approach. Gradient terms motivated by the $p$-wave resonance $\Sigma (1385)$ are found to play a secondary role for single-$K^{-}$-nuclear systems where the mean-field concept is acceptable. Significant contributions from the $\overline{K}N\to \pi \Lambda$ conversion mode, and from the nonmesonic $\overline{K}\mathit{NN}\to \mathit{YN}$ conversion modes, which are assumed to follow a ${\rho }^2$ density dependence, are evaluated for the deep binding-energy range of over 100 MeV where the decay channel $\overline{K}N\to \pi \Sigma$ is closed. Altogether we obtain $K^{-}$ total decay widths of 50–100 MeV for binding energies exceeding 100 MeV in single-$K^{-}$ nuclei. Multi-$\overline{K}$-nuclear calculations indicate that the binding energy per $\overline{K}$ meson saturates upon increasing the number of $\overline{K}$ mesons embedded in the nuclear medium. The nuclear and $\overline{K}$ densities increase only moderately and are close to saturation, with no indication of any kaon-condensation precursor.

The phase-space paths introduced by Cheuk-Yin Wong in Phys. Rev. C [25, 1460 (1982)] and discussed recently in the literature can be used for calculation of the evolution of the Wigner function to the first order in time increments only. The first-order solutions are helpful in the determination the phase-space Green function in the framework of the phase-space path integral method.

We give the exact solution of orbit dependent nuclear pairing problem between two nondegenerate energy levels using the Bethe ansatz technique. Our solution reduces to previously solved cases in the appropriate limits including Richardson's treatment of reduced pairing in terms of rational Gaudin algebra operators.

How to identify the orbital of the valence nucleon(s) of exotic nuclei is an important problem. The elastic magnetic electron scattering is an excellent probe to determine the valence structure of odd-$A$ nuclei. The relativistic mean-field theory has been successfully applied to systematic studies of the elastic charge electron scattering from even-even exotic nuclei. The extension of this method to investigate the elastic magnetic electron scattering from odd-$A$ exotic nuclei is a natural generalization. The experimental form factors of ${}^{17}\mathrm{O}$ and ${}^{41}\mathrm{Ca}$ are reproduced very well with the help of the spectroscopic factors which are introduced into the relativistic treatment of the magnetic electron scattering for the first time. The emphases are put on the magnetic form factors of ${}^{15,17,19}\mathrm{C}$, ${}^{23}\mathrm{O}$, ${}^{17}\mathrm{F}$, and ${}^{49,59}\mathrm{Ca}$ calculated in the relativistic impulse approximation. Great differences have been found in the form factors of the same nucleus with different configurations. Therefore, the elastic magnetic electron scattering can be used to determine the orbital of the last nucleon of odd-$A$ exotic nuclei. Our results can provide references for the electron scattering from exotic nuclei in the near future.

Net charge fluctuations in a hadron gas are studied using an effective hadronic interaction. The emphasis of this work is to investigate the corrections of hadronic interactions to the charge fluctuations of a noninteracting resonance gas. Several methods such as loop, density, and virial expansions are employed. The calculations are also extended to SU(3), and some resummation schemes are considered. Although the various corrections are sizable individually, they cancel to a large extent. As a consequence, we find that charge fluctuations are rather well described by the free resonance gas.

The freeze-out procedure accepted in a model of three-fluid dynamics is analyzed. This procedure is formulated in terms of drain terms in hydrodynamic equations. The dynamics of freeze-out is illustrated by one-dimensional simulations. It is demonstrated that the resulting freeze-out reveals a nontrivial dynamics depending on initial conditions in the expanding “fireball.” The freeze-out front is not just defined “geometrically” on the condition of the freeze-out criterion met but rather is a subject of fluid evolution. It competes with the fluid flow and does not always reach the place where the freeze-out criterion is met. Dynamics of the freeze-out in three-dimensional simulations is analyzed. It is demonstrated that the late stage of central nuclear collisions at the top energies available at the CERN Super Proton Synchrotron is of the form of three (two baryon-rich and one baryon-free) fireballs separated from each other.