A modified Woods-Saxon potential model is proposed for a unified description of the entrance channel fusion barrier and the fission barrier of fusion-fission reactions based on the Skyrme energy-density functional approach. The fusion excitation functions of 120 reactions were systematically studied. The fusion (capture) cross sections are well described with the calculated potential and an empirical barrier distribution. Incorporating a statistical model (HIVAP code) for describing the decay of the compound nucleus, the evaporation residue (and fission) cross sections of 51 fusion-fission reactions have been systematically investigated. Optimal values of some key parameters of the HIVAP code are obtained based on the experimental data of these reactions. The experimental data are reasonably well reproduced by the calculated results. The upper and lower confidence limits of the systematic errors of the calculated results are given.

Inelastic proton scattering on ${}^{12}\mathrm{Be}$ was investigated by microscopic coupled-channel calculations with the theoretical wave function of ${}^{12}\mathrm{Be}$ obtained by antisymmetrized molecular dynamics. The experimental angular distribution of the inelastic scattering into ${}^{12}\mathrm{Be}$${}^{*}(2_1^{+})$ is successfully reproduced by the largely deformed states with dominant $\mathit{sd}$-shell configuration in the ground band. The radial dependence of the transition density for ${}^{12}\mathrm{Be}$$(2_1^{+})\to$${}^{12}\mathrm{Be}$$(0_1^{+})$ is quite different between protons and neutrons. It gives significant effects on the relation of the neutron transition strength to the inelastic cross section.

A systematic study of the pairing correlations as a function of temperature and angular momentum was performed in the sd-shell region using the spherical shell model approach. Pairing correlations were derived for even-even, even-odd, and odd-odd systems near $N=Z$ and also for the asymmetric case of $N=Z+4$. The results indicate that the pairing content and the behavior of pair correlations is similar in even-even and odd-mass nuclei. For the odd-odd $N=Z$ system, angular momentum $I=0$ state is an isospin, $t=1$ neutron-proton paired configuration. Further, these $t=1$ correlations are shown to be dramatically reduced for the asymmetric case of $N=Z+4$. The shell model results obtained are qualitatively explained within a simplified degenerate model.

The low-lying yrast states in the ${}^{51}\mathrm{Ca}$ and ${}^{52}\mathrm{Sc}$ nuclei were investigated to obtain information on the evolution of the $p_{1/2}$ and $f_{5/2}$ neutron single-particle orbitals in neutron-rich nuclei near proton number $Z=20$. Level structures associated with neutron excitations into these two orbitals and with proton excitations across the $Z=20$ shell gap were identified. Shell-model calculations with the recently proposed GXPF1A interaction account reasonably well for the $\mathit{fp}$-shell states. The energy separation between the $\nu p_{1/2}$ and $\nu f_{5/2}$ orbitals in the Ca isotopes appears to be overestimated by the GXPF1A Hamiltonian.

The differential cross sections of quasi-elastic scattering at backward angles were measured with high precision for ${}^{32}\mathrm{S}+{}^{90,96}\mathrm{Zr}$ around the Coulomb barrier, and barrier distributions were extracted from the measured excitation functions. The experimental barrier distribution of ${}^{32}\mathrm{S}+{}^{90}\mathrm{Zr}$ is well reproduced by the coupled-channels calculations including the low-lying quadruple and octupole vibrations in ${}^{32}\mathrm{S}$ and ${}^{90}\mathrm{Zr}$. However, the model with the same coupling scheme fails to reproduce the experimental barrier distribution for ${}^{32}\mathrm{S}+{}^{96}\mathrm{Zr}$. The coupled-channels calculation including the neutron transfer channels in the system ${}^{32}\mathrm{S}+{}^{96}\mathrm{Zr}$ gives an improved description of the experimental data. A comparison of the data on ${}^{40}\mathrm{Ca}+{}^{90,96}\mathrm{Zr}$ shows that the two systems ${}^{32}\mathrm{S}$, ${}^{40}\mathrm{Ca}+{}^{90}\mathrm{Zr}$ display barrier distributions that are similar to each other, whereas the barrier distributions of ${}^{32}\mathrm{S}$, ${}^{40}\mathrm{Ca}+{}^{96}\mathrm{Zr}$ are both wider and flatter than the those of ${}^{40}\mathrm{Ca}+{}^{90,96}\mathrm{Zr}$. The present results strongly indicate that neutron transfer plays an important role in the fusion processes.

Two inequalities are derived which set upper and lower bounds on the intensity of two partially coherent interfering beams. These bounds are obtained from the observed interference pattern. Further, one establishes the connection between these inequalities and the “duality relation” obtained in the context of which-way information in two-path interferometry experiments.

For laboratory kinetic energies between 50 and 200 MeV, we focus on generating an energy-dependent Lorentz covariant parametrization of the on-shell nucleon-nucleon ($\mathit{NN}$) scattering amplitudes in terms of a number of Yukawa-type meson exchanges in first-order Born approximation. This parametrization provides a good description of $\mathit{NN}$ scattering observables in the energy range of interest, and can also be successfully extrapolated to energies between 40 and 300 MeV.

We study number of spin $I$ states for bosons in this article. We extend Talmi's recursion formulas for number of states with given spin $I$ to boson systems, and we prove empirical formulas for five bosons by using these recursions. We obtain number of states with given spin $I$ and $F$ spin for three and four bosons by using sum rules of six-$j$ and nine-$j$ symbols. We also present empirical formulas of states for $d$ bosons with given spin $I$ and $F=F_{\max }-1$ and $F_{\max }-2$.

Thermal properties of asymmetric nuclear matter are studied within a self-consistent thermal model using an isospin and momentum-dependent interaction (MDI) constrained by the isospin diffusion data in heavy-ion collisions, a momentum-independent interaction (MID), and an isoscalar momentum-dependent interaction (eMDYI). In particular, we study the temperature dependence of the isospin-dependent bulk and single-particle properties, the mechanical and chemical instabilities, and liquid-gas phase transition in hot asymmetric nuclear matter. Our results indicate that the temperature dependence of the equation of state and the symmetry energy are not so sensitive to the momentum dependence of the interaction. The symmetry energy at fixed density is found to generally decrease with temperature and for the MDI interaction the decrement is essentially due to the potential part. It is further shown that only the low momentum part of the single-particle potential and the nucleon effective mass increases significantly with temperature for the momentum-dependent interactions. For the MDI interaction, the low momentum part of the symmetry potential is significantly reduced with increasing temperature. For the mechanical and chemical instabilities as well as the liquid-gas phase transition in hot asymmetric nuclear matter, our results indicate that the boundaries of these instabilities and the phase-coexistence region generally shrink with increasing temperature and are sensitive to the density dependence of the symmetry energy and the isospin and momentum dependence of the nuclear interaction, especially at higher temperatures.

We discuss the energy loss of energetic parton jets in quark-gluon plasma above the deconfinement temperature $T_c$ by the interaction with scalar and pseudoscalar glueballs. It is shown that the loss by this mechanism is quite important and may play the important role of the observed jet quenching.

We estimate the higher-twist contributions using Nachtmann moments, which provide a method for handling target mass corrections. The corrections to the Cornwall-Norton moments of nucleon spin structure functions are also addressed. Their sizable role in the twist-3 ${\tilde{d}}_2^{p,n,d}$ extracted from the Cornwall-Norton moments is discussed. Moreover, their role in the isoscalar and isovector structure functions is also shown.

Neutron matter at low density is studied within the hole-line expansion. Calculations are performed in the range of Fermi momentum $k_F$ between 0.4 and 0.8 fm${}^{-1}$. It is found that the Equation of State is determined by the ${}^1{S}_0$ channel only, the three-body forces contribution is quite small, the effect of the single particle potential is negligible and the three hole-line contribution is below 5% of the total energy and indeed vanishing small at the lowest densities. Despite the unitary limit is actually never reached, the total energy stays very close to one half of the free gas value throughout the considered density range. A rank one separable representation of the bare $\mathit{NN}$ interaction, which reproduces the physical scattering length and effective range, gives results almost indistinguishable from the full Brueckner G-matrix calculations with a realistic force. The extension of the calculations below $k_F=0.4$ fm${}^{-1}$ does not indicate any pathological behavior of the neutron matter equation of state.

We present the solution to the recently derived Wilsonian renormalization group (RG) equation for nuclear current operators. To eliminate the present ambiguity in the RG equation itself, we introduce a new condition specifying the cutoff independence of the five-point Green function corresponding to the two-body propagator with current operator insertion. The resulting effective current operator is then shown to obey a modified Ward-Takahashi identity that differs from the usual one, but that nevertheless leads to current conservation.

The $\gamma$ rays following the ${}^{94,95}\mathrm{Mo}$$(n,\gamma )$ reactions were measured as a function of incident neutron energy by the time-of-flight method with the DANCE (Detector for Advanced Neutron Capture Experiments) array of 160 ${\mathrm{BaF}}_2$ scintillation detectors at the Los Alamos Neutron Science Center. The targets were enriched samples: 91.59% ${}^{94}\mathrm{Mo}$ and 96.47% ${}^{95}\mathrm{Mo}$. The $\gamma$-ray multiplicities and energy spectra for different multiplicities were measured in $s$- and $p$-wave resonances up to $E_n=10$ keV for ${}^{94}\mathrm{Mo}$ and up to $E_n=2$ keV for ${}^{95}\mathrm{Mo}$. Definite spins and parities were assigned in ${}^{96}\mathrm{Mo}$ for about 60% of the resonances, and tentative spins and parities were assigned for the remaining resonances. In ${}^{95}\mathrm{Mo}$ the parities were determined for the observed resonances, confirming previously known assignments.

In the present work, we calculate the ${}^{208}\mathrm{Pb}$ neutron skin thickness, binding energy, surface energy, and density profiles within the Dirac solution of a density dependent hadronic model. The same calculation is performed with the NL3 parametrization of the nonlinear Walecka model. The asymmetry of a polarized electron scattered from a heavy target is also obtained within a partial wave expansion calculation. The theoretical results are then ready to be compared with the experimental results expected to be available very soon at the Thomas Jefferson National Accelerator Facility. For completeness, other nuclei such as ${}^{40}\mathrm{Ca}$, ${}^{48}\mathrm{Ca}$, ${}^{66}\mathrm{Ni}$, and ${}^{90}\mathrm{Zr}$ are also investigated.

Green's function Monte Carlo (GFMC) calculations of magnetic dipole, electric quadrupole, Fermi, and Gamow-Teller transition matrix elements are reported for $A=6,7$ nuclei. The matrix elements are extrapolated from mixed estimates that bracket the relevant electroweak operator between variational Monte Carlo (VMC) and GFMC propagated wave functions. Because they are off-diagonal terms, two mixed estimates are required for each transition, with a VMC initial (final) state paired with a GFMC final (initial) state. The realistic Argonne $v_{18}$ two-nucleon and Illinois-2 three-nucleon interactions are used to generate the nuclear states. In most cases we find good agreement with experimental data.

Particle-number projection is applied to the modified BCS (MBCS) theory. The resulting particle-number-projected MBCS theory, taking into account the effects due to fluctuations of particle and quasiparticle numbers at finite temperature, is tested within the exactly solvable multilevel model for pairing as well as the realistic ${}^{120}\mathrm{Sn}$ nucleus. The signature of the pseudogap in the crossover region above the critical temperature of superfluid-normal phase transition is discussed in terms of the pairing spectral function.

A Gammasphere experiment was carried out to search for triaxial strongly deformed (TSD) structures in ${}^{171,172}\mathrm{Hf}$ and the wobbling mode, a unique signature of nuclei with stable triaxiality. Three strongly deformed bands in ${}^{172}\mathrm{Hf}$ and one in ${}^{171}\mathrm{Hf}$ were identified through ${}^{48}\mathrm{Ca}$(${}^{128}\mathrm{Te}$, xn) reactions. Linking transitions were established for the band in ${}^{171}\mathrm{Hf}$ and, consequently, its excitation energies and spins (up to $111/2\hslash$) were firmly established. However, none of the ${}^{172}\mathrm{Hf}$ sequences were linked to known structures. Experimental evidence of triaxiality was not observed in these bands. The new bands are compared with other known strongly deformed bands in neighboring Hf isotopes. Theoretical investigations within various models have been performed. Cranking calculations with the Ultimate Cranker code suggest that the band in ${}^{171}\mathrm{Hf}$ and two previously proposed TSD candidates in ${}^{170}\mathrm{Hf}$ and ${}^{175}\mathrm{Hf}$ are built on proton $(i_{13/2}{h}_{9/2})$ configurations, associated with near-prolate shapes and deformations enhanced with respect to the normal deformed bands. Cranked relativistic mean-field calculations suggest that band 2 in ${}^{175}\mathrm{Hf}$ has most likely a near-prolate superdeformed shape involving the $\pi i_{13/2}\otimes \nu j_{15/2}$ high-$j$ intruder orbitals. It is quite likely that the bands in ${}^{172}\mathrm{Hf}$ are similar in character to this band.

Energy correlations in transitions from the bound state to the three-body continuum of Borromean halo nuclei are considered. A core$+n+n$ three-body cluster model which reproduces the experimentally known properties of ${}^6\mathrm{He}$ and ${}^{11}\mathrm{Li}$ has been used to study the low-lying resonances and soft modes. An analysis of the correlated responses in ${}^6\mathrm{He}$ shows that in the case of the narrow three-body $2_1^{+}$ resonance the transition energy correlations are the same as in the intrinsic correlated structure in $3\to 3$ scattering. They differ significantly for wide $2_2^{+},1_1^{+}$ resonances, and also for the soft dipole and monopole modes, where, due to the transition operators, the intertwining of the ground state and the three-body continuum plays a significant role.

The preliminary NA49 results on the energy dependence of transverse-momentum fluctuations over the whole Super Proton Synchrotron (SPS) energy range exhibit an unexpected effect. The ${\Phi }_{p_T}$ fluctuation measure—used by the NA49 experiment—manifests a different behavior for different charge combinations. Whereas the ${\Phi }_{p_T}$ is consistent with zero and independent of energy for negatively charged particles, it significantly increases for both all charged and positively charged particles at lower SPS energies. The string-hadronic ultrarelativisic quantum molecular dynamics model (UrQMD) is applied here to explain this effect. The UrQMD simulations show that the number of protons is strongly correlated with impact parameter and that the event-by-event impact parameter fluctuations are responsible for the event-by-event transverse-momentum fluctuations of positively charged and all charged particles where protons are included. The observations presented in this article are important for all experiments measuring event-by-event fluctuations, especially for those using all charged particles in the analysis. The results can be also crucial for detectors with acceptances extending to the beam/target spectator domains.