In the framework of the resonating-group method, the interactions of decuplet baryon-baryon systems with strangeness numbers $s=-1$ and $s=-5$ are investigated by employing the chiral SU(3) quark model. The effective baryon-baryon interactions deduced from quark-quark interactions and scattering cross sections of the ${\Sigma }^{*}\Delta$ and ${\Xi }^{*}\Omega$ systems are calculated.

We use proton-nucleus reaction data at intermediate energies to test the emerging new generation of chiral nucleon-nucleon $\mathrm{}\left(\mathrm{NN}\right)\mathrm{}$ potentials. Predictions from a high-quality one-boson-exchange (OBE) force are used for comparison and evaluation. Both the chiral and OBE models fit $\mathrm{NN}$ phase shifts accurately, and the differences between the two forces for proton-induced reactions are small. A comparison to a chiral model with a less accurate $\mathrm{NN}$ description sets the scale for the ability of such models to work for nuclear reactions.

We exploit a relationship between the structure functions of nucleons, the physical deuteron, and of a deuteron, composed of point-nucleons to compute angular distributions of inclusive cross sections of 4.05 GeV electrons. We report general agreement with data and interpret the remaining discrepancies. We discuss the potential of the data for information on neutron structure functions $F_k^n{(x,Q}^2)$ and the static form factor $G_M^n{(Q}^2).\mathrm{}$

We discuss and explore new aspects of the generalized Dyson mapping of nuclear collective superalgebras composed of an arbitrary fermion-pair algebra and a set of single-fermion creation/annihilation operators. It is shown that a direct consequence of the particular mapping procedure is the conservation of the total number of ideal particles in the resulting boson-fermion system. This provides a microscopic framework for the phenomenological supersymmetric models based on the $\mathrm{U}(6/2\mathrm{}\Omega )$ dynamical superalgebras. Attention is paid to the mapping of single-fermion creation and annihilation operators whose detailed form cannot be determined on the phenomenological level. We derive the general expansion of the single-fermion images that result from the similarity transformation employed to ensure nonredundant bosonization in the ideal space. The method is then illustrated in an application to the SO(4) collective algebra, a natural extension of the SU(2) seniority model.

An approach is proposed to calculate the direct reaction (DR) and fusion probabilities for heavy ion collisions at near-Coulomb-barrier energies as functions of the distance of the closest approach D within the framework of the optical model that introduces two types of imaginary potentials, DR and fusion. The probabilities are calculated by using partial DR and fusion cross sections, together with the classical relations associated with the Coulomb trajectory. Such an approach makes it possible to analyze the data for angular distributions of the inclusive DR cross section, facilitating the determination of the radius parameters of the imaginary DR potential in a less ambiguous manner. Simultaneous ${\chi }^2$ analyses are performed of relevant data for the ${}^{16}\mathrm{O}{+}^{208}\mathrm{Pb}$ system near the Coulomb-barrier energy.

The differential cross section for the $p\overrightarrow{d}{}^3\mathrm{He}\eta$ reaction has been measured at four beam energies 930, 965, 1037, and 1100 MeV. The total cross section is nearly constant throughout the whole energy region, despite the c.m. angular distribution becoming more anisotropic with increasing energy. The data join smoothly onto the results of near-threshold measurements, which are dominated by the S-wave $\eta {}^3\mathrm{He}$ final state interaction. At all the energies the differential cross section is maximal for $\cos {\theta }_{\eta }\approx +0.5\mathrm{}$ and this may provide a clue to the reaction mechanism and, in particular, to two-step contributions.

The doubly differential cross sections for the ${}^4\mathrm{He}({\pi }^{+},{\pi }^{-})4p$ reaction were calculated using both a two-nucleon sequential single charge exchange model and an intranuclear cascade code. Final state interactions between the two final protons which were the initial neutrons were included in both methods. At incident pion energies of 240 and 270 MeV the low-energy peak observed experimentally in the energy spectrum of the final pions can be understood only if the contribution of pion production is included. The calculated cross sections are compared with data.

We present the first measurement of midrapidity vector meson $\phi$ production in Au+Au collisions at RHIC $(\sqrt{s_{\mathrm{NN}}}=130\mathrm{}\hspace{0.5em}\mathrm{GeV})$ from the STAR detector. For the 11% highest multiplicity collisions, the slope parameter from an exponential fit to the transverse mass distribution is $T=379\mathrm{}\pm 50\left(\mathrm{stat}\right)\pm 45\left(\mathrm{syst}\right)\hspace{0.5em}\mathrm{MeV},$ the yield $dN/dy=5.73\mathrm{}\pm 0.37\left(\mathrm{stat}\right)\pm 0.69\left(\mathrm{syst}\right)$ per event, and the ratio $N_{\phi }{/N}_{h^{-}}$ is found to be $0.021\pm 0.001\left(\mathrm{stat}\right)\pm 0.004\left(\mathrm{syst}\right).\mathrm{}$ The measured ratio $N_{\phi }{/N}_{h^{-}}$ and T for the $\phi$ meson at midrapidity do not change for the selected multiplicity bins.

The interplay of pairing and other interactions is addressed in this work using a simple single-$j$ model. We show that enhancements in pairing correlations, observed through studies of the spectra of deformed systems, moments of inertia, changes in transitional multipole amplitudes, and direct calculations of the pairing component in the wave function, indicate that even without explicit matrix elements responsible for pairing, a paired state can still appear from the kinematic coupling of pairing to deformation and from other geometrical restrictions that are of extreme importance in mesoscopic systems. Furthermore, we demonstrate that macroscopic transitions such as oblate to prolate shape changes can lead to strong dynamic enhancements of pairing correlations. In this work we emphasize that the pairing condensate has an important dynamic and kinematic effect on other residual interactions.

The geometric analysis of the interacting boson model-1 is performed for a rotating reference frame using the condensate-state approximation. It is shown that the rotation leads to triaxial nuclear shapes and to modifications (dependent on the angular frequency ω) of the critical parameter value for the deformed-spherical phase transition. These modifications are reflected by the structure of actual yrast states with higher angular momenta.

We study the effect of enforcing exact conservation of charges in statistical models of particle production for systems as large as those relevant to relativistic heavy ion collisions. By using a numerical method developed for small systems, we have been able to approach the large volume limit keeping the exact canonical treatment of all relevant charges, namely, baryon number, strangeness, and electric charge. Hence, we hereby give the information needed in a hadron gas model whether the canonical treatment is necessary or not in actual cases. Comparison between calculations and experimental particle multiplicities is shown. Also, a discussion on relative strangeness chemical equilibrium is given.

Employing an extended three flavor version of the Nambu–Jona-Lasinio model, we discuss in detail the phase diagram of quark matter. The presence of quark as well as of diquark condensates gives rise to a rich structure of the phase diagram. We study in detail the chiral phase transition and the color superconductivity as well as color flavor locking as a function of the temperature and chemical potentials of the system.

Previous neutron-proton total cross-section difference measurements $\Delta {\sigma }_L$ and $\Delta {\sigma }_T$ between $E_n=7.43\mathrm{}$ and 17.1 MeV have been analyzed in a new way that reduces experimental systematic uncertainties. The results obtained for the ${}^3{S}_1{-}^3{D}_1$ mixing parameter ${\epsilon }_1$ are very similar to the published values, substantiating the previous conclusion that the nucleon-nucleon tensor force at low energies is stronger than predicted by the Nijmegen partial-wave analysis and, therefore, by all the recent high-precision nucleon-nucleon potential models as well.

The Nijmegen NSC89 and the most recent NSC97 hyperon-nucleon potentials are adopted to study the structures of hypernuclei. Investigations are concentrated on the hypernucleus ${}_{\Lambda }^{40}\mathrm{Ca}$ by using our two-frequency shell-model folded-diagram approach. We first calculate the $\mathrm{YN}$ G matrix with an exact Pauli exclusion operator. The nucleon frequency for the harmonic oscillator basis wave function is chosen from the empirical formula $ħ{\omega }_N{=45A}^{-1/3}-{25A}^{-2/3},$ while the hyperon one is obtained as the frequency when the lowest hyperon single-particle energy in the hypernucleus reaches a saturation minimum. The energy-independent effective interaction $V_{\mathrm{eff}}$ is then obtained from the $\mathrm{YN}$ G matrix elements, using a $\mathrm{Q̂}$-box folded-diagram framework. We will examine how our calculated spectra vary via these different versions of the realistic hyperon-nucleon potentials. Special attention is drawn on the contribution of the $\Lambda N-\Sigma N$ coupling diagram. Although this diagram contributes significantly to $V_{\mathrm{eff}}$ in most cases, it does not alter much to the final spectrum.

The three moments of inertia associated with the wobbling mode built on the superdeformed states in ${}^{163}\mathrm{Lu}$ are investigated by means of the cranked shell model plus random phase approximation to the configuration with an aligned quasiparticle. The result indicates that it is crucial to take into account the direct contribution to the moments of inertia from the aligned quasiparticle so as to realize ${\mathcal{J}}_x>{\mathcal{J}}_y$ in positive-$\gamma$ shapes. Quenching of the pairing gap cooperates with the alignment effect. The peculiarity of the recently observed ${}^{163}\mathrm{Lu}$ data is discussed by calculating not only the electromagnetic properties but also the excitation spectra.

The influence of the ground-state spin of fusing nuclei on the subsequent fission fragment angular distributions has been investigated through realistic quantum-mechanical calculations. The domain of applicability of an approximate formula is found for spherical nuclei. For deformed nuclei, a generalization of the standard transition state model expression for the fission fragment angular distribution is presented. This predicts dramatic changes in the shape and anisotropy of the distribution, for reactions of deformed nuclei with large ground-state spin.

We study a dynamical chiral bag model, in which massless fermions are confined within an impenetrable but movable bag coupled to meson fields. The self-consistent motion of the bag is obtained by solving the equations of motion exactly assuming spherical symmetry. When the bag interacts with an external meson wave we find three different kinds of resonances: fermionic, geometric, and $\sigma$ resonances. We discuss the phenomenological implications of our results.

The processes ${}^3\mathrm{He}\to \left(\overrightarrow{e}{,e}^{\prime }\right)$ and ${}^3\mathrm{He}\to \left(\overrightarrow{e}{,e}^{\prime }n\right)$ are theoretically analyzed with the aim to search for sensitivities in the electric form factor of the neutron, $G_E^n.$ Faddeev calculations based on the high-precision $\mathrm{NN}$ force AV18 and using consistent mesonic exchange currents are employed. While the inclusive process is too insensitive, the semiexclusive one appears promising.

A 25 MeV/nucleon primary ${}^{17}\mathrm{O}$ beam was used to produce an isomeric state ${}^{18}{\mathrm{F}}^m$ beam via the single-nucleon transfer reaction ${}^{17}\mathrm{O}$ ${(}^{12}\mathrm{C},$ ${}^{11}\mathrm{B})$${}^{18}{\mathrm{F}}^m.$ The total nuclear reaction cross section, ${\sigma }_R,$ of ${}^{18}{\mathrm{F}}^m$ (metastable) on silicon was measured using a stack of silicon surface barrier detectors that included a position sensitive silicon detector (PSD). The total reaction cross sections were determined as a function of bombarding energy up to 400 MeV by measuring the energy loss in each detector. The reaction cross sections were measured both for a mixture of metastable- and ground-state ions and for a pure ground-state beam. The reaction cross sections for ${}^{14}\mathrm{N}$ and ${}^{16}\mathrm{O}$ beams were also measured simultaneously. The reaction cross sections for the metastable beam were deduced from the mixed- and the ground-state cross sections, corrected for the measured purity of the mixed-state beam. The observed reaction cross sections for ${}^{18}{\mathrm{F}}^m$ are larger at low energies than the cross sections measured for the ground state. The isomeric cross sections can be reproduced by an optical model potential having a diffuseness of 0.8 fm, compared to a more conventional diffuseness parameter of 0.5 fm, which is adequate to reproduce the ${}^{14}\mathrm{N},$ ${}^{16}\mathrm{O},$ and ${}^{18}{\mathrm{F}}_{\mathrm{g}.\mathrm{s}.\mathrm{}}$ cross sections measured in this experiment.

We try to single out some qualitative effects of coupling to a δ-isovector-scalar meson, introduced in a minimal way in a phenomenological hadronic field theory. Results for the equation of state (EOS) and the phase diagram of asymmetric nuclear matter (ANM) are discussed. We stress the consistency of the δ-coupling introduction in a relativistic approach. Contributions to the slope and curvature of the symmetry energy and to the neutron-proton effective mass splitting appear particularly interesting. A more repulsive EOS for neutron matter at high baryon densities is expected. Effects on the critical properties of warm ANM, mixing mechanical and chemical instabilities and isospin distillation, are also presented. The δ influence is mostly on the isovectorlike collective response. The results are largely analytical, and this makes the physical meaning quite transparent. Implications for nuclear structure properties of drip-line nuclei and for reaction dynamics with radioactive beams are finally pointed out.