Three-nucleon forces, which compose an up-to-date subject in few-nucleon systems, provide a good account of the triton binding energy and the cross section minimum in proton-deuteron elastic scattering. However, three-nucleon forces do not explain spin observables such as the nucleon and deuteron analyzing powers, suggesting serious defects in their spin dependence. We study the spin structure of nucleon-deuteron elastic amplitudes by decomposing them into spin-space tensors and examine effects of three-nucleon forces to each component of the amplitudes obtained by solving the Faddeev equation. Assuming that the spin-scalar amplitudes dominate the others, we derive simple expressions for spin observables in the nucleon-deuteron elastic scattering. The expressions suggest that a particular combination of spin observables in the scattering provides direct information on scalar, vector, or tensor component of the three-nucleon forces. These effects are numerically investigated by the Faddeev calculation.

A self-consistent factorization of the two-body residual interaction in random-phase approximation (RPA) is proposed for density- and current-dependent nuclear energy functionals. Following this procedure, a separable RPA (SRPA) method is constructed. SRPA provides a reliable approximation to exact RPA while considerably simplifying the calculations. The method is tested and exemplified for the Skyrme forces SkI3 and SkM*.

A simple technique is described that provides an improved nearside-farside (NF) method for elastic scattering amplitudes. The technique, involving the novel resummation of a Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can arise in more conventional NF decompositions. Detailed applications are made to a strong absorption model and to a ${}^{16}\mathrm{O}{+}^{16}\mathrm{O}$ optical potential at $E_{\mathrm{lab}}=145\mathrm{}\mathrm{MeV}.$ We also discuss ${}^{16}\mathrm{O}{+}^{16}\mathrm{O}$ at $E_{\mathrm{lab}}=480,$ 704, 1120 MeV, and $\alpha {+}^{12}\mathrm{C},$ $\alpha {+}^{40}\mathrm{Ca},$ both at $E_{\mathrm{lab}}=1370\mathrm{}\mathrm{MeV}.$

An alternative parametrization of $\mathit{R}$-matrix theory is presented which is mathematically equivalent to the standard approach, but possesses features that simplify the fitting of experimental data. In particular, there are no level shifts and no boundary-condition constants which allow the positions and partial widths of an arbitrary number of levels to be easily fixed in an analysis. These alternative parameters can be converted to standard $\mathit{R}$-matrix parameters by a straightforward matrix diagonalization procedure. In addition, it is possible to express the collision matrix directly in terms of the alternative parameters.

The nucleus ${}^{183}\mathrm{Au}$ was studied via lifetime measurements using the Doppler shift recoil distance method. The reaction used was ${}^{159}\mathrm{Tb}{(}^{28}\mathrm{Si}{,4n)}^{183}\mathrm{Au}$ at a beam energy of 140 MeV. Transition probabilities were measured for the levels of two important bands based on $i_{13/2}$ and $h_{9/2}$ intruder configurations. The quadrupole moments extracted from measured lifetimes are $\sim 24\%$ larger for the $i_{13/2}$ band when compared with the $h_{9/2}$ band. The total Routhian surface calculations have been carried out using the cranked Hartree-Fock-Bogoliubov model. The calculations also support a larger deformation for the $i_{13/2}$ configuration as compared to the $h_{9/2}$ configuration.

We discuss various measures of net charge (conserved quantities) fluctuations proposed for the identification of critical phenomena in heavy ion collisions. We show the dynamical component of fluctuations of the net charge can be expressed simply in terms of integrals of two- and single-particle densities. We discuss the dependence of the fluctuation observables on detector acceptance, detection efficiency and colliding system size, and collision centrality. Finally, we present a toy model of particle production including charge conservation and resonance production to gauge the effects of such resonances and finite acceptance on the net-charge fluctuations.

We present a nonrelativistic coupled-channel calculation of the deuteron structure including $\Delta \Delta$ and ${\mathrm{NN}}^{*}\mathrm{}\left(1440\right)\mathrm{}$ channels, besides the standard $\mathrm{NN}$ S- and D-wave components. All the necessary building blocks to perform the calculation have been obtained from the same underlying quark model. The calculated ${\mathrm{NN}}^{*}\mathrm{}\left(1440\right)\mathrm{}$ probabilities find support in the explanation given to different deuteron reactions.

The $N=86,87\mathrm{}$ isotopes of dysprosium and holmium have been investigated using the Eurogam II $\gamma$-ray spectrometer. A new collective rotational band has been observed in ${}^{153}\mathrm{Ho}$ and the previously observed $\nu {\mathrm{i}}_{13/2}$ band in ${}^{153}\mathrm{Dy}$ has been extended to much higher spin. Comparing these bands and similar bands in ${}^{152}\mathrm{Dy}$ with the collective bands in the $N=90\mathrm{}$ isotopes of Dy, Ho, and Er suggests that the first $h_{11/2}$ proton crossing is not observed at $N=86,87.\mathrm{}$ This observation has led to the reinterpretation of four of the previously observed bands in ${}^{152}\mathrm{Dy}.$ It is proposed that the low deformation collective bands in ${}^{152,153}\mathrm{Dy}$ and ${}^{153}\mathrm{Ho}$ are associated with a triaxial shape with large positive gamma and that they have a similar origin to the recently observed triaxial superdeformed bands in ${}^{163–165}\mathrm{Lu}.$

The low-lying collective states involving many nucleons interacting by the two-body random ensemble (TBRE) interactions are investigated in a collective $\mathrm{SD}$-pair subspace, with the collective pairs defined by the two-nucleon system. It is found that in this truncated pair subspace, collective vibrations arise naturally for a general TBRE Hamiltonian whereas collective rotations do not. A Hamiltonian restricted to include only a few randomly generated separable terms is able to produce collective rotational behavior, as long as it includes a reasonably strong quadrupole-quadrupole component. Similar results arise in the full shell model space. These results suggest that the structure of the Hamiltonian is key to producing generic collective rotation.

The first complete measurements of the angular distributions of the two-body deuteron photodisintegration differential cross section at photon energies above 1.6 GeV were performed at the Thomas Jefferson National Accelerator Facility. The results show a persistent forward-backward asymmetry up to $E_{\gamma }=2.4\mathrm{}\mathrm{GeV},$ the highest-energy measured in this experiment. The Hard Rescattering and the Quark-Gluon string models are in fair agreement with the results.

Using the covariant spectator theory and the transversity formalism, the unpolarized, coincidence cross section for deuteron electrodisintegration, ${d(e,e}^{\prime }p)n,$ is studied. The relativistic kinematics are reviewed, and simple theoretical formulas for the relativistic impulse approximation (RIA) are derived and discussed. Numerical predictions for the scattering in the high $Q^2$ region obtained from the RIA and five other approximations are presented and compared. We conclude that measurements of the unpolarized coincidence cross section and the asymmetry $A_{\phi },$ to an accuracy that will distinguish between different theoretical models, is feasible over most of the wide kinematic range accessible at Jefferson Lab.

The two-proton emission process ${}^3\mathrm{He}{(e,e}^{\prime }pp)n$ is theoretically investigated using realistic three-nucleon wave functions and taking the final state interaction into account by an approach which can be used when the value of the three-nucleon invariant mass is either below or above the pion emission threshold. Various kinematical conditions which enhance or minimize the effects of the final state interaction are thoroughly analyzed.

The isoscalar $E1\mathrm{}$ and $E2\mathrm{}$ resonances in the proton-rich nuclei ${}^{48,49}\mathrm{Ni}$ and the $\{f_{7/2}\otimes 3^{-}\}$ multiplet in ${}^{49}\mathrm{Ni}$ have been calculated taking into account the single-particle continuum exactly. The analogous calculations for the mirror nuclei ${}^{48}\mathrm{Ca}$ and ${}^{49}\mathrm{Sc}$ are presented. The models used are the continuum random-phase approximation (RPA) for ${}^{48}\mathrm{Ni},$ ${}^{48}\mathrm{Ca}$ and the odd RPA for ${}^{49}\mathrm{Ni},$ ${}^{49}\mathrm{Sc},$ where the latter has been developed recently and describes both single particle and collective excitations of an odd nucleus on a common basis. In all four nuclei, we obtained a distinct splitting of the isoscalar $E1\mathrm{}$ resonance into $1ħ\omega$ and $3ħ\omega$ peaks at about 11 MeV and 30 MeV, respectively. The main part of the isoscalar $E1\mathrm{}$ energy-weighted sum rule (EWSR) is exhausted by the $3ħ\omega$ resonances. The $1ħ\omega$ resonances exhaust about 35% of this EWSR in ${}^{48,49}\mathrm{Ni}$ and about 22% in ${}^{48}\mathrm{Ca}$ and ${}^{49}\mathrm{Sc}.$ All seven $\{f_{7/2}\otimes 3^{-}\}$ multiplet members in ${}^{49}\mathrm{Ni}$ are calculated to be in the 6–8 MeV energy region and have noticeable escape widths.

Fusion cross sections were measured for the ${}^{6,7}\mathrm{Li}{+}^{27}\mathrm{Al},$ ${}^{64}\mathrm{Zn}$ systems, at energies above the Coulomb barrier, in order to study the influence of the breakup of stable weakly bound nuclei on the fusion process. The analysis was completed by the inclusion of the data of fusion induced by ${}^9\mathrm{Be}$ and the strongly bound ${}^{16}\mathrm{O}$ and ${}^{11}\mathrm{B}$ projectiles on the same targets. The fusion excitation functions have similar behavior for all projectiles incident on both targets and they show no indication of fusion hindrance.

The Coulomb dissociation of ${}^8\mathrm{B}$ on high-$Z$ targets can be described by first-order perturbation theory at high beam energies but the far-field approximation, which is commonly used, becomes inaccurate at impact parameters less than $\sim 25\mathrm{fm}.$ The leading-order correction at lower beam energies is a dynamic polarization effect, which reduces the dissociation probability. The relative significance of the effect scales roughly as $Z/E$ in terms of the target charge Z and beam energy E. The reduction due to a destructive Coulomb-nuclear interference, on the other hand, is rather modest.

We present a method for constructing the complete set of meson-exchange corrections to baryon observables described by covariant chiral quark models. The meson corrections are expressed in terms of an unperturbed valence-quark Green’s function. This method is illustrated for the case of a Nambu–Jona-Lasinio model. It also enables us to discuss, in terms of approximations used for this unperturbed Green’s function, the treatments of meson corrections in two other chiral quark models.

Within a light-cone QCD formalism incorporating color transparency, coherence length effects, and gluon shadowing, we study electroproduction of $J/\Psi$ off nuclei. In contrast to light vector meson production when at small and medium energies color transparency and coherence length effects are not easily separated, in charmonium production color transparency effects dominate. We found rather large color transparency effects in the range of $Q^2<~20{\mathrm{GeV}}^2.$ They are stronger at low than at high energies and can be easily identified by the planned future experiments. Model calculations explain well the data of the New Muon Collaboration on the $Sn/C$ ratio of nuclear transparencies as a function of the photon energy. We provide predictions for incoherent and coherent charmonium production for future measurements.

The ${}^1{S}_0$ n-p scattering length $a_{\mathrm{np}}$ has been measured using the n-d breakup reaction at 25 MeV. The experiment was performed in a geometry where the neutron and proton were detected in coincidence at the same angle. The data were analyzed with rigorous three-nucleon calculations using realistic nucleon-nucleon potentials. The result of $a_{\mathrm{np}}=-24.3\pm 1.1\mathrm{fm}$ agrees with the well-known value from free n-p scattering, and also with previous results from n-d breakup experiments which were performed in different geometries.

The quantum-number-projected generator coordinate method with the monopole- and quadrupole-pairing plus quadrupole-quadrupole interaction is studied in reference to the low-lying and high-spin states in ${}^{130,132}\mathrm{Xe}.$ The energy spectra obtained by this method are compared to the shell model results and the experimental data. The quasi-$\gamma$ bands as well as the yrast sequences are well reproduced. The triaxial shapes play essential roles in describing the quasi-$\gamma$ bands.

We investigate the relation between different three-dimensional reductions of the Bethe-Salpeter equation and the analytic structure of the resultant amplitudes in the energy plane. This correlation is studied for both the ${\phi }^2\sigma$ interaction Lagrangian and the $\pi N$ system with s-, u-, and t-channel pole diagrams as driving terms. We observe that the equal-time equation, which includes some of the three-body unitarity cuts, gives the best agreement with the Bethe-Salpeter result. This is followed by other three-dimensional approximations that have less of the analytic structure.