It is shown that the nuclear symmetry energy is the key quantity in the stability consideration in neutron star matter. The symmetry energy controls the position of crust-core transition and also may lead to new effects in the inner core of neutron star.

The ${\beta }^{-}$ decay of the exotic ${}^{30}\mathrm{Ne}$ ($N=20$) is reported. For the first time, the low-energy level structure of the $N=19$, ${}^{30}\mathrm{Na}$ ($T_Z=4$), is obtained from β-delayed γ spectroscopy using fragment-$\beta \text{−}\gamma \text{−}\gamma$ coincidences. The level structure clearly displays “inversion,” i.e., intruder states with mainly $2p2h$ configurations displacing the normal states to higher excitation energies. The good agreement in excitation energies and the weak and electromagnetic decay patterns with Monte Carlo shell model calculations with the SDPF-M interaction in the $\mathit{sdpf}$ valence space confirms the small $d_{3/2}\text{−}{f}_{7/2}$ shell gap. The relative position of the normal dominant and intruder dominant excited states provides valuable information to understand better the $N=20$ shell gap.

The high-spin structure of the ${}^{105}\mathrm{Ag}$ nucleus has been studied by using the ${}^{100}\mathrm{Mo}$(${}^{10}\mathrm{B}$, $5n)$${}^{105}\mathrm{Ag}$ reaction to search for chiral doublet bands based on the three-quasiparticle $\pi g_{9/2}\nu (h_{11/2}){}^2$ configuration. The level scheme of ${}^{105}\mathrm{Ag}$ has been extended. New bands were found and the placement of the yrast $\pi g_{9/2}\nu (h_{11/2}){}^2$ band was corrected. No side band to the yrast $\pi g_{9/2}\nu (h_{11/2}){}^2$ band could be found in the present experiment. This observation indicates that the γ-soft shape in the ${}^{106}\mathrm{Ag}$ changed to a more γ-rigid axially symmetric shape in the yrast ${}^{105}\mathrm{Ag}$ configuration. However, a new pair of bands was observed to show the expected properties of a chiral doublet structure.

Multiplicity fluctuations are studied in the van der Waals excluded volume hadron-resonance gas model. The calculations are done in the grand canonical ensemble within the Boltzmann statistics approximation. The scaled variances for positive, negative, and all charged hadrons are calculated along the chemical freeze-out line of nucleus-nucleus collisions at different collision energies. The multiplicity fluctuations are found to be suppressed in the van der Waals gas. The numerical calculations are presented for two values of the hard-core hadron radius, $r=0.3$ and 0.5 fm, as well as for the upper limit of the excluded volume suppression effects.

The multiplicity distributions of hadrons produced in central nucleus-nucleus collisions are studied within the hadron-resonance gas model in the large-volume limit. The microscopic correlator method is used to enforce conservation of three charges—baryon number, electric charge, and strangeness—in the canonical ensemble. In addition, in the microcanonical ensemble energy conservation is included. An analytical method is used to account for resonance decays. The multiplicity distributions and the scaled variances for negatively, positively, and all charged hadrons are calculated along the chemical freeze-out line of central $\mathrm{Pb}+\mathrm{Pb}$ ($\mathrm{Au}+\mathrm{Au}$) collisions from GSI Schwerionen Synchrotron to CERN Large Hadron Collider energies. Predictions obtained within different statistical ensembles are compared with the preliminary NA49 experimental results on central $\mathrm{Pb}+\mathrm{Pb}$ collisions in the SPS energy range. The measured fluctuations are significantly narrower than the Poisson ones and clearly favor expectations for the microcanonical ensemble. Thus this is the first observation of the recently predicted suppression of the multiplicity fluctuations in relativistic gases in the thermodynamical limit owing to conservation laws.

We discuss the measured nuclear suppression of $p+\overline{p}$ production in $200A$ GeV Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) within radiative energy loss. For the Albino-Kniehl-Kramer (AKK) set of fragmentation functions, proton production is dominated by gluons, giving rise to the expectation that the nuclear suppression for $p+\overline{p}$ should be stronger than for pions due to the stronger coupling of gluons to the quenching medium. Using a hydrodynamical description for the soft matter evolution, we show that this is indeed seen in the calculation. However, the expected suppression factors for pions and protons are sufficiently similar that a discrimination with present data is not possible. In the high $p_T$ region above 6 GeV where the contributions of hydrodynamics and recombination to hadron production are negligible, the model calculation is in good agreement with the data on $p+\overline{p}$ suppression.

Four-body equations in momentum space are solved for neutron-${}^3\mathrm{He}$, proton-${}^3\mathrm{H}$, and deuteron-deuteron scattering; all three reactions are coupled. The Coulomb interaction between the protons is included using the screening and renormalization approach as was recently done for proton-deuteron and proton-${}^3\mathrm{He}$ scattering. Realistic potentials are used between nucleon pairs. For the first time fully converged results for the observables pertaining to the six different elastic and transfer reactions are obtained and compared with experimental data.

We studied the roles of the tensor and pairing correlations on the halo formation in ${}^{11}\mathrm{Li}$ with an extended ${}^9\mathrm{Li}+n+n$ model. We first solved the ground state of ${}^9\mathrm{Li}$ in the shell-model basis by taking 2p-2h states using the Gaussian functions with variational size parameters to take into account the tensor correlation fully. In ${}^{11}\mathrm{Li}$, the tensor and pairing correlations in ${}^9\mathrm{Li}$ are Pauli blocked by additional two neutrons, which work coherently to make the configurations containing the $0p_{1/2}$-state pushed up and close to those containing the $1s_{1/2}$-state. Hence, the pairing interaction works efficiently to mix the two configurations by equal amount and develop the halo structure in ${}^{11}\mathrm{Li}$. For ${}^{10}\mathrm{Li}$, the inversion phenomenon of $s$- and $p$-states is reproduced in the same framework. Our model furthermore explains the recently observed Coulomb breakup strength and charge radius for ${}^{11}\mathrm{Li}$.

The experimental energy staggering in γ bands of rare earths and actinides exhibits three distinct patterns as a function of angular momentum that are typical of well-deformed structural benchmarks: γ-soft for nuclei situated between a vibrator and a deformed γ-soft structure, axially symmetric for those between a vibrator and a rigid rotor, and triaxial γ-rigid for nuclei between a vibrator and a rigid triaxial rotor. The three patterns are reproduced by appropriate special solutions of the Bohr Hamiltonian, as well as by interacting boson approximation calculations. A particular quantity called S(4), which is proportional to the displacement of the $3_{\gamma }^{+}$ level relative to the average of the $2_{\gamma }^{+}$ and $4_{\gamma }^{+}$ levels, can vary in magnitude and sign for different shapes and is found to give a good indication of structure and the evolution of structure. A sudden change in the γ-band staggering occurring between the vibrator and the axially symmetric rotor limits seems to be connected to the known presence of a first-order phase/shape transition in this region.

A method for identifying statistical equilibrium stages in dynamical multifragmentation paths as provided by transport models, already successfully tested for the reaction ${}^{129}\mathrm{Xe}$$+{}^{119}$Sn at 32 MeV/nucleon is applied here to a higher energy reaction, ${}^{129}\mathrm{Xe}$$+{}^{119}$Sn at 50 MeV/nucleon. The method evaluates equilibrium from the point of view of the microcanonical multifragmentation model (MMM) and reactions are simulated by means of the stochastic mean field model (SMF). A unique solution, corresponding to the maximum population of the system phase space, was identified suggesting that a huge part of the available phase space is occupied even in the case of the 50 MeV/nucleon reaction, in presence of a considerable amount of radial collective flow. The specific equilibration time and volume are identified and differences between the two systems are discussed.

Four 1-cm${}^3$ CdZnTe semiconductor detectors were operated in the Gran Sasso National Laboratory to explore the feasibility of such devices for double β-decay searches as proposed for the COBRA experiment. The research involved background studies accompanied by measurements of energy resolution performed at the surface. Energy resolutions sufficient to reduce the contribution of two-neutrino double β-decay events to a negligible level for a large-scale experiment have already been achieved and further improvements are expected. Using activity measurements of contaminants in all construction materials a background model was developed with the help of Monte Carlo simulations and major background sources were identified. A total exposure of 4.34 kg·days of underground data have been accumulated allowing a search for neutrinoless double β-decay modes of seven isotopes found in CdZnTe. Half-life limits (90% C.L.) are presented for decays to ground and excited states. Four improved lower limits have been obtained, including zero neutrino double electron capture transitions of ${}^{64}\mathrm{Zn}$ and ${}^{120}\mathrm{Te}$ to the ground state, which are $1.19\times {10}^{17}$ years and $2.68\times {10}^{15}$ years, respectively.

We argue that estimates of dissipative effects based on first-order hydrodynamics with shear viscosity are potentially misleading because higher order terms in the gradient expansion of the dissipative part of the stress tensor tend to reduce them. Using recently obtained sound dispersion relations in thermal $\mathcal{N}=4$ supersymmetric plasma, we calculate the resummed effect of these high-order terms for Bjorken expansion appropriate to heavy ion collisions such as those performed at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). A reduction of entropy production is found to be substantial, up to an order of magnitude.

Color Glass Condensate (CGC) provides a classical description of dense gluon matter at high energies. Using the McLerran-Venugopalan (MV) model we calculate the initial energy density $\varepsilon (\tau )$ in the early stage of the relativistic nucleus-nucleus collision. Our analytical formula reproduces the quantitative results from lattice discretized simulations and leads to an estimate $\varepsilon (\tau =0.1\mathrm{fm})=40~50\mathrm{GeV}·{\mathrm{fm}}^{-3}$ in the (central) Au-Au collision at BNL Relativistic Heavy Ion Collider. We then formulate instabilities with respect to soft fluctuations that violate boost invariance inherent in hard CGC backgrounds. We find unstable modes arising, which are attributed to ensemble average over the initial CGC fields.

In this work we analyze the validity of recently proposed extensions of the Quasiparticle Random Phase Approximation (QRPA). Particularly, we focus our attention on the Fully Renormalized QRPA (FRQRPA). We found that the results of this approximation do not differ from the results of the QRPA. This finding is supported by a detailed comparison between both formalisms, their assumptions and approximations, in the context of realistic calculations.

It has been claimed recently that half-lives of radioactive nuclei embedded in metals would be significantly affected by electron screening provided by the metal. The effect would further be strengthened at low temperatures. We have determined the half-life-of ${}^{253}\mathrm{Es}$ nuclei embedded in iron at temperatures between 4 K and 50 mK. Our results agree with the room temperature literature value within about 2% and show no dependence on temperature over a range of almost two orders of magnitude.

With a sophisticated effective gluon propagator, Maris-Tandy model, we solve the Dyson-Schwinger equation to get the quark propagator and then study the soliton solution in the global color model (GCM). Along the constraints on the parameters fitted to the pion decay constant, we take several sets of parameters and find that some of the properties of soliton can be produced in the GCM soliton model with a special choice of parameters. We also discuss the influences of the parameters and the ultraviolet perturbative term on the property of the soliton. We find that the interaction among quarks is the one with self-adjusting characteristic and only the fine-tuned interaction can generate an appropriate solition, but not that much stronger attraction produces more stable soliton.

We perform a global analysis of all recent experimental data from elastic parity-violating electron scattering at low $Q^2$. The values of the electric and magnetic strange form factors of the nucleon are determined at $Q^2=0.1\mathrm{GeV}/c^2$ to be $G_E^s=-0.008\pm 0.016$ and $G_M^s=0.29\pm 0.21$.

Charge exchange spin-dipole (SD) excitations in ${}^{90}\mathrm{Zr}$ and ${}^{208}\mathrm{Pb}$ are studied by using a Skyrme Hartree-Fock + random phase approximation. The calculated spin-dipole strength distributions are compared with experimental data obtained by ${}^{90}\mathrm{Zr}$(p,n)${}^{90}\mathrm{Nb}$ and ${}^{90}\mathrm{Zr}$(n,p)${}^{90}\mathrm{Nb}$ reactions. The model-independent SD sum rule values of various Skyrme interactions are studied in comparison with the experimental values to determine the neutron skin thickness of ${}^{90}\mathrm{Zr}$. The pressure of the neutron matter equation of state and the nuclear matter symmetry energy are discussed in terms of the neutron skin thickness and peak energies of SD strength distributions.

We investigate the consistency of the measured charge radius and dipole response of ${}^{11}\mathrm{Li}$ within a three-body model. We show how these observables are related to the mean-square distance between the ${}^9\mathrm{Li}$ core and the center of mass of the two valence neutrons. In this representation we find by considering the effect of smaller corrections that the discrepancy between the results of the two measurements is of the order of $1.5\sigma$. We also investigate the sensitivity to the three-body structure of ${}^{11}\mathrm{Li}$ and find that the charge radius measurement favors a model with a 50% s-wave component in the ground state of the two-neutron halo, whereas the dipole response is consistent with a smaller s-wave component of about 25% value.

The dynamic polarization potential (DPP) contribution to the effective proton-nucleus interaction, that is due to the coupling of deuteron channels, is evaluated by applying $S_{\mathit{lj}}\to V(r)$ inversion to the elastic channel $S$-matrix from coupled reaction channel calculations of proton elastic scattering. This was done for protons scattering from ${}^{10}\mathrm{Be}$ at 12, 13, 14, 15, and 16 MeV; nonorthogonality corrections were included. We find a consistent pattern of a repulsive real and an absorptive imaginary DPP, with the absorption shifted to a larger radius. This is consistent with what has been found for proton scattering from the neutron skin nucleus ${}^8\mathrm{He}$. The DPP is not of a form that can be represented by a renormalization of the bare potential, and has properties suggesting an underlying nonlocal process. We conclude that deuteron channels cannot be omitted from a full theoretical description of the proton-nucleus interaction (optical potential).