We have measured 14 spin observables for pp elastic scattering at 730 MeV and extracted the isospin-one amplitudes directly from the data. These new data complete the 730-MeV data set to the same standard as the 580-, 650-, and 800-MeV data.

A nonrelativistic nucleon-nucleon (NN) coupled channels isobar model is used to calculate nuclear medium corrections to the first-order Watson optical potential for nucleon-nucleus scattering. The NN interaction includes π, 2π, ρ, η, and ω exchange for the pure nucleonic sector, one-pion exchange for nucleon-isobar coupling, and phenomenological short-range interactions for both the diagonal and coupling terms. Good fits to NN elastic phase shifts from 0–1 GeV have been obtained with this model. The specific nuclear medium effects studied here include Pauli blocking of intermediate nucleon scattering states and off-shell binding energy shifts. On-momentum-shell matrix elements of the density dependent, effective NN t matrix are used to calculate the local proton-nucleus optical potential assuming the local density approximation. The model is applied to proton elastic scattering from ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ at 320, 400, 500, 650, and 800 MeV and the predictions are compared with available data. In general, the medium modifications significantly affect the nonrelativistic predictions, even at 800 MeV, and bring about a substantial, overall improvement in the description of differential cross section and spin observable data. The improvements occur for each case and at all angles studied, but the agreement is most successful for forward angle differential cross sections and for spin observable data from 1 to 3 ${\mathrm{fm}}^{\mathrm{-}1}$. Deficiencies remain in the density dependent, nonrelativistic predictions for the forward angle spin observables where relativistic models are quite successful. The relation of this work to other nonrelativistic models which include nuclear medium corrections, off-shell effects, and full-folding contributions is also discussed.

Doubly differential cross sections of the reaction ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$(n,p${)}^{90}$Y have been measured at 198 MeV for excitations up to 38 MeV in the residual nucleus. An overall resolution of 1.3 MeV was achieved. The spectra show qualitative agreement in shape and magnitude with recent random phase approximation calculations; however, all of the calculations underestimate the high excitation region of the spectra. A multipole decomposition of the data has been performed using differential cross sections calculated in the distorted-wave impulse approximation. An estimate of the Gamow-Teller strength in the reaction is given. The isovector spin-flip dipole giant resonance has been identified and there is also an indication of isovector monopole strength.

The derivation of the low energy theorem for threshold photoproduction of neutral pions on a nucleon is reconsidered. Instead of considering explicitly the Born terms, as done in earlier derivations, a more general class of diagrams is separated from the total amplitude. Gauge invariance is imposed on the operator level and the partial conservation of the axial-vector current constraint is incorporated. Besides recovering the older results in this approach, relations for the off-shell behavior of the strong and electromagnetic vertices are derived.

Distorted-wave impulse approximation formalism in momentum space including the averaging over nucleon Fermi motion is presented for the case of nuclear pion photoproduction. Representative examples of the partial transitions on the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ nuclei at several photon energies are compared with the data and discussed. This has enabled us to focus clearly on the successes and limitations in the present understanding of the nuclear photoproduction field.

The half-life of ${}_{}{}^{176}{}_{}{}^{}\mathrm{Lu}$ was deduced using Ge γ-ray spectrometry from the mass and activity of a lutetium oxide sample enriched in ${}_{}{}^{176}{}_{}{}^{}\mathrm{Lu}$. The half-life was found to be 4.05±0.09×${10}^{10}$ y. The relative intensities of the γ rays were also measured and are compared to previously reported values.

Hyperfine structures and isotope shifts of strontium isotopes with A=78 to A=98 and A=100 were measured by collinear fast beam laser spectroscopy. Nuclear spins, moments and changes in mean square charge radii are extracted from the data. The spins and moments of most of the odd isotopes are explained in the framework of the single particle model. The changes in mean square charge radii are compared with predictions of the droplet model and of Hartree-Fock-plus-BCS calculations. For the isotopes in the transitional regions below and above the N=50 shell closure, the inclusion of quadrupole zero point motion in the Droplet model describes part of the observed shell effect. An additional change in the surface region of the charge distribution at spherical shape is suggested by the microscopic model. Furthermore, we propose that the isotopes ${}_{}{}^{78}{}_{}{}^{}\mathrm{Sr}$ and ${}_{}{}^{80}{}_{}{}^{}\mathrm{Sr}$ may show an unusual shape-sharing structure, with different mean deformations in the ground and $2_1^{+}$ excited states.

The negative-parity states of odd xenon and odd barium isotopes have been interpreted within the framework of the interacting boson-fermion model where the multi-orbit boson-fermion interaction is simplified. Comparisons with observed energy spectra as well as other model calculations are made.

The simple nuclear Ramsauer model is extended to include explicitly the isovector potential. This model predicts large differences between proton and neutron total nuclear cross sections. When this model is applied to isotope/isotone total neutron cross section differences, it gives a good description of the measured data in the mass 140 region. Non-isospin-dependent differences in the isotopic imaginary potential are observed which totally obscure the contribution from the isovector imaginary potential. Additional measurements further from closed nuclear shells may yield useful information on the isovector imaginary potential.

The moments of inertia of ${\mathit{K}}^{\mathrm{\pi }}$=$0^{+}$ bands in the well-deformed nuclei are calculated by a particle-number-conserving treatment for the cranked shell model. The very accurate solutions to the low-lying ${\mathit{K}}^{\mathrm{\pi }}$=$0^{+}$ bands are obtained by making use of an effective K truncation. Calculations show that the main contribution to the moments of inertia comes from the nucleons in the intruding high-j orbits. Considering the fact that no free parameter is involved in the calculation and no extra inert core contribution is added, the agreement between the calculated and the observed moments of inertia of $0^{+}$ bands in ${}_{}{}^{168}{}_{}{}^{}\mathrm{Er}$ is very satisfactory.

A Fourier transform ion cyclotron resonance (ICR) mass spectrometer has been used to measure the relative masses of five of the stable isotopes of xenon. The precision of these measurements is comparable to that of the reference mass values (Atomic Mass Table). When the measured ICR frequencies are used to check the mass table values of ${}_{}{}^{129}{}_{}{}^{}\mathrm{Xe}$ through ${}_{}{}^{136}{}_{}{}^{}\mathrm{Xe}$ for internal consistency, a significant error in the mass of ${}_{}{}^{134}{}_{}{}^{}\mathrm{Xe}$ is indicated.

The ${(}^6$Li${,}^6$He) reaction was studied on targets of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$, and ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ at a beam energy of 156 MeV. Zero degree measurements of all systems are presented. The evaluated cross sections for Gamow-Teller transitions at θ=0° and the corresponding strengths of analogous beta decays are compared.

Measurements of the analyzing power ${\mathit{A}}_{\mathit{y}}$(θ) have been made for the elastic scattering of neutrons from ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$ at 17 MeV. Over most of the angular range the data agree with predictions derived from the previously reported coupled-channels analysis for ${}_{}{}^{116,120}{}_{}{}^{}\mathrm{Sn}$(n,n) of Guss et al.

The ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{28}$Si,X${)}^{11}$C cross section was measured for 13.4-GeV/nucleon ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ ions. Beam intensities were determined with a two-element counter telescope, and the ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ activity induced in thin and thick plastic scintillator targets was assayed by internal scintillation counting. The cross section corrected to zero target thickness is 73.5±3.5 mb. This value is compared with similar measurements for relativistic projectiles at 1–2 GeV/nucleon.

Chance near degeneracy of rotational states in the 1/$2^{\mathrm{-}}$[521] and 5/$2^{\mathrm{-}}$[512] bands in ${}_{}{}^{175}{}_{}{}^{}\mathrm{Os}$ leads to mixing and connecting E2 transitions. Analysis of the observed branching ratios gives an interaction matrix element of about 4 keV, an order of magnitude smaller than the expected Coriolis interaction, deduced from particle-rotor calculations. A difference in deformation of 25% between the two configurations, as suggested by the larger unperturbed moment of inertia in the 1/$2^{\mathrm{-}}$[521] band, would explain the quenched interaction.

The SU(3) limit of the interacting boson model is considered from the perspective of the 1/N expansion. We show that truncation of the E2 matrix elements in the spirit of the 1/N expansion and the Mikhailov plots greatly simplifies the complicated exact results and leads to some new insights. A list of E2 transitions among the ground, β, and γ bands, both in the SU(3) limit and in more general cases, is given, and some errors in the previous literature are pointed out.

We estimate that the electrodisintegration of the deuteron contributes at least 25% of the total reaction cross section when the deuteron interacts with a nucleus of charge Z≳40 at a kinetic energy lower than 50 MeV. The neglect of this breakup channel in deuteron-nucleus optical potentials might lead to unrealistic predictions for the mass and energy dependence of the total deuteron reaction cross sections.

The dispersive contribution to the real part of the optical potential arising due to the energy dependence of the imaginary part of the potential has been estimated for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{12}$C, ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ systems.