The possibility of creating exotic nuclei by means of multinucleon transfer processes in reactions with radioactive beams has been explored. In this paper we estimate the magnitude of the modifications in the population patterns for the different mass partitions that take place as the newly formed systems get rid of their excitation energy by particle emission.

In Dirac phenomenology, a large Coulomb-nuclear interference term appears in the effective potential of the Schrödinger-like equation equivalent to the Dirac equation. This is apparently in strong contrast with the nonrelativistic approach and could be checked by a comparative study of neutron- and proton-nucleus scattering. A detailed calculation in a realistic case shows, however, that the interference effect is elusive.

Prompt, in-beam $\gamma$ rays following the reaction ${}_{}{}^{170}{}_{}{}^{}\mathrm{Yb}$ + 142 MeV ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ were measured at the ATLAS facility using 10 Compton-suppressed Ge detectors and the Fragment Mass Analyzer. Transitions in ${}_{}{}^{194}{}_{}{}^{}\mathrm{Po}$ were identified and placed using $\gamma$-ray singles and coincidence data gated on the mass of the evaporation residues. A level spectrum up to $J\approx 10\hslash$ was established. The structure of ${}_{}{}^{194}{}_{}{}^{}\mathrm{Po}$ is more collective than that observed in the heavier polonium isotopes and indicates that the structure has started to evolve toward the more collective nature expected for deformed nuclei.

Fusion-evaporation cross sections have been measured for ${}_{}{}^{32,36}{}_{}{}^{}\mathrm{S}$+${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}$ to high accuracy in the energy range around the Coulomb barrier. The two extracted fusion barrier distributions display very similar structures with two well-resolved peaks below the nominal barrier, which are consistent with a model calculation including the coupling of the one-, two-, and three-phonon collective vibrations of ${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}$. A third lower-energy barrier, together with a strong relative cross section enhancement, is observed for ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$+${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}$, and is reproduced by coupling the two-neutron pickup channel which has a large and positive ground state $Q$ value (+5.1 MeV). For ${}_{}{}^{36}{}_{}{}^{}\mathrm{S}$+${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}$, the calculated effect of the corresponding transfer channel (with negative $Q$ value) is much smaller.

The ${}_{}{}^2{}_{}{}^{}\mathrm{H}(\overrightarrow{p}, \gamma ){}_{}{}^3{}_{}{}^{}\mathrm{He}$ reaction has been studied in the energy region $E_p=80-0\mathrm{}$ keV ($E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=53.3-0\mathrm{}$ keV), where the quantities measured were $\sigma (\theta , E)$ and $A_y(\theta , E)$. Our result for the total ${}_{}{}^2{}_{}{}^{}\mathrm{H}(p, \gamma ){}_{}{}^3{}_{}{}^{}\mathrm{He}$ $S$ factor at $E=0\mathrm{}$ is $S\left(0\right)=0.121\mathrm{}\pm 0.012$ eV b (including systematic error), which is 52% lower than the presently accepted value. Some astrophysical aspects of this result are discussed. We have also extracted the $E1\mathrm{}$ and $M1\mathrm{}$ $S\left(E\right)\mathrm{}$ components using our detailed angular distribution data. These data will provide sensitive tests for three-body calculations which include Coulomb and meson exchange current effects.

Through a sequence of large scale $0\hslash \omega$ shell model calculations, Gamow-Teller strengths ($S_{+}$ and $S_{-}$) in ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$ and ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ are obtained. They reproduce the experimental values by quenching the $\sigma \tau$ operator through the standard factor of 0.77. Comparisons are made with recent shell model Monte Carlo calculations. Results are shown to depend critically on the interaction. It is argued that the experimental data contain enough strength in the region above the resonance to make them consistent with the $3(N-Z)\mathrm{}$ sum rule.

Exact diagonalizations with a realistic interaction show that configurations with four neutrons in a major shell and four protons in another—or the same—major shell, behave systematically as backbending rotors. The dominance of the q⋅q component of the interaction is related to an approximate ‘‘quasi-SU3’’ symmetry. It is suggested that the onset of rotational motion in the rare earth nuclei is due to the promotion of the eight particle blocks to the major shells above the ones currently filling. Assuming a ‘‘pseudo-SU3’’ coupling for the particles in the lower orbits, it is possible to account remarkably well for the observed B(E2) rates at the beginning of the region.

The equilibration of the isospin degree of freedom in intermediate energy heavy-ion collisions was studied using an isospin-dependent BUU model. It is found that there exists a transition from the isospin equilibration at low energies to nonequilibration at high energies as the beam energy varies across the Fermi energy in central, asymmetric, heavy-ion collisions. At beam energies around 55 MeV/nucleon the composite system is in almost complete thermal equilibrium but isospin nonequilibrium breaks up into two primary hot residues with $\frac{N}{Z}$ ratios closely related to those of the target and projectile, respectively. The decay of these forward-backward moving residues results in the strong isospin asymmetry in space and the dependence of the isotopic composition of fragments on the $\frac{N}{Z}$ ratios of the target and projectile. These features are in good agreement with those found recently in experiments at NSCL/MSU and TAMU; implications of these findings are discussed.

The nucleon's strange form factors $G_E^S\left(Q^2\right)$ and $G_M^S\left(Q^2\right)$, and the neutron's electromagnetic form factors $G_E^n\left(Q^2\right)$ and $G_M^n\left(Q^2\right)$, are obtained from the light-cone quark model including the quark anomalous moments due to the meson-loop corrections. The anomalous magnetic and strange moments of the constituent quark make significant contributions: Without them, $G_M^S\mathrm{}\left(0\right)\mathrm{}$ vanishes, $r_S^2$ becomes positive, and the neutron charge radius is too small.

The experimental cold-fission yields for the system ${}_{}{}^{233}{}_{}{}^{}\mathrm{U}(n_{\mathrm{th}}, f)$ are analyzed as function of the effective total excitation energy (TXE). The nuclear level density effect is taken into account at higher TXE, in order to benefit by the lower experimental data uncertainty as well as to avoid the quantitative account of the level densities close to fragment ground states. In this way the odd-even staggering which appears in the yields extrapolated at zero excitation energy by using the level densities, vanishes. We conclude that the cold nuclear fragmentation theory including the dynamical model describes well the experimental data.

In two different phase transition models of nuclear fragmentation we show that the emission of pre-equilibrium particles and mixing of events from different classes cannot be ignored in the analysis of nuclear fragmentation data in terms of critical exponents, and we show how the apparent values of the extracted exponents are affected.

The density-dependent relativistic mean-field theory with $\sigma$, $\omega$, and $\rho$ mesons, as a parameter-free calculation, has been used to study the ground-state properties of ${}_{}{}^{12,14}{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{30,32}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{60,62}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{122,124}{}_{}{}^{}\mathrm{Zr}$. A special emphasis is placed on the influence of the $\rho$ tensor coupling on the neutron halo and on the spin-orbit splitting. It is shown for the first time that the inclusion of the $\rho$ tensor coupling will lead to the isospin-dependent spin-orbit splitting although the binding energy and the radius of these nuclei are insensitive to it.

The $\rho$-meson contribution to the $\Lambda N\to \mathrm{NN}$ process is studied in the nonmesonic decay of hypernuclei. It is found that the central potential of the $\rho$ exchange is larger than its tensor part and, therefore, must be included. This is in contrast to the $\pi$-exchange term which is dominated by the tensor interaction.

All the vector and tensor analyzing powers of the p+d scattering have been measured at ${\mathit{E}}_{\mathit{p}}^{\mathrm{lab}}$=2.5 MeV (${\mathit{E}}_{\mathit{d}}^{\mathrm{lab}}$=5 MeV), where a calculation of the three-nucleon scattering state with an improved treatment of Coulomb force has become available. Measurements have also been made at energies below and slightly above the deuteron breakup threshold at ${\mathit{E}}_{\mathit{p}}^{\mathrm{lab}}$ = 3.34 MeV. The experimental data have small statistical errors ranging from ±0.0004 to ±0.0008, and the uncertainties in the scale are less than 1%. The present data together with our previous data on the cross section are compared with several Faddeev calculations based on a separable-form nucleon-nucleon potential or on a realistic potential with Coulomb force being treated nearly correctly or approximately. Disagreements between the calculations and the experiment are found not only in the cross section and the vector analyzing powers ${\mathit{A}}_{\mathit{y}}$ and ${\mathit{iT}}_{11}$ but also in the tensor analyzing powers ${\mathit{T}}_{21}$ and ${\mathit{T}}_{22}$.

High partial waves for pp and np elastic scattering are examined critically from 210 to 800 MeV. Non-one-pion-exchange contributions are compared with predictions from theory. There are some discrepancies, but sufficient agreement that values of the πNN coupling constants ${\mathit{g}}_0^2$ for ${\mathrm{\pi }}^0$ exchange and ${\mathit{g}}_{\mathit{c}}^2$ for charged π exchange can be derived. Results are ${\mathit{g}}_0^2$=13.94±0.17±0.07 and ${\mathit{g}}_{\mathit{c}}^2$=13.69±0.15±0.24, where the first error is statistical and the second is an estimate of the systematic error arising from uncertainties in the normalization of total cross sections and dσ/dΩ.

Elastic nucleon scattering from the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ mirror nuclei is considered as a possible test of charge symmetry violation. The differential cross sections at 500 MeV are calculated using a microscopic, momentum-space optical potential including the full coupling of two spin-1/2 particles and an exact treatment of the Coulomb force. The charge-symmetry-breaking effects investigated arise from a violation within the nuclear structure, from the p-nucleus Coulomb force, and from the mass differences of the charge symmetric states. Measurements likely to reveal reliable information are noted.

Inclusive electron scattering data on ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ are analyzed under full treatment of the final state interactions (FSI) using realistic nucleon-nucleon forces. The data are well described. We use two different methods, one where we calculate the pd and ppn breakup contributions separately and another one which is related to the optical theorem for Compton scattering. Both rely on precise solutions of Faddeev-like equations and agree perfectly. The importance of FSI and the inclusion of total isospin T=3/2 for the full breakup of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ is demonstrated. We also comment on the Coulomb sum rule and the extraction of the proton-proton correlation function.

Nucleon polarization in exclusive electrodisintegration of the deuteron using a polarized beam and an oriented target is systematically investigated in a nonrelativistic framework but with lowest order relativistic contributions to the one-body current including the kinematic part of the wave function boost. The structure functions and the asymmetries corresponding to the various nucleon polarization components are studied with respect to their sensitivity to the potential model, to subnuclear degrees of freedom, and to relativistic effects in different kinematical regions. Furthermore, a few new observables are found which are very sensitive to the neutron electric form factor ${\mathit{G}}_{\mathit{En}}$ in the quasifree region.