The neutron deficient ${}_{}{}^{77}{}_{}{}^{}\mathrm{Sr}$ nucleus was studied by fast ion beam collinear laser spectroscopy with a detection scheme based on optical pumping, state selective neutralization, and atom counting. From the measured hyperfine splitting and isotope shift of the Sr II transition 5s ${}_{}{}^2{}_{}{}^{}$${\mathit{S}}_{1/2}$→5p ${}_{}{}^2{}_{}{}^{}$${\mathit{P}}_{3/2}$ the nuclear spin I=5/2, the nuclear moments μ=-0.348(4)${\mathrm{\mu }}_{\mathit{N}}$, ${\mathit{Q}}_{\mathit{s}}$=1.40(11) b, and the change in mean square charge radius δ〈${\mathit{r}}^2$${\mathrm{〉}}^{88,77}$=0.248(12) ${\mathrm{fm}}^2$ were deduced. These ground-state properties indicate a large prolate deformation of ${\mathrm{\epsilon }}_2$≃0.4 and allow a comparison with calculations performed in the particle-plus-deformed-core model, assigning a [422]5/2 Nilsson configuration to the ground state of ${}_{}{}^{77}{}_{}{}^{}\mathrm{Sr}$.

The possibility of strong tensor coupling of the (isoscalar) ω(783) meson to hyperons, specifically Λ(1115), has been suggested by several authors during the past decade. This paper studies the effect of this coupling on magnetic properties of hypernuclei, within the framework of the (minimal) σ+ω model. Our results are analytical and intuitive. They provide physical insight into recent numerical results of Gattone, Chiapparini, and Izquierdo. Additionally, we point out similar effects in transition form factors at moderate momentum transfer, on finite nuclei.

We study the positions at which fragments are formed in the nuclear breakup of Kr and Xe induced by high energy protons, and find that they are consistent with a uniform fragment production over the entire nuclear volume.

Using sum rules and Fermi-liquid theory an explanation for the observed probe dependence of the quasielastic peak is offered.

The nucleus-nucleus potentials (${\mathit{V}}_{\mathit{N}}$) over a range of interaction distances (-2<S<2.5 fm) have been obtained from the analyses of the fusion excitation function data spanning a large range of energies. A three-parameter Fermi function adequately represents the observed variation of ${\mathit{V}}_{\mathit{N}}$/R¯[R=${\mathit{R}}_1$${\mathit{R}}_2$/(${\mathit{R}}_1$+${\mathit{R}}_2$), with ${\mathit{R}}_1$ and ${\mathit{R}}_2$ the radii of the interacting nuclei] with S in the above-mentioned range.

The experimental values of ${\log }_{10}$${\mathit{T}}_{1/2}$(sec) plotted vs ${\mathit{Z}}_{\mathit{d}}^{0.6}$/ √${\mathit{Q}}_{\mathrm{\alpha }}$ are shown to fall on a nearly universal straight line with ${\log }_{10}$${\mathit{T}}_{1/2}$(sec)=(9.54${\mathit{Z}}_{\mathit{d}}^{0.6}$/ √${\mathit{Q}}_{\mathrm{\alpha }}$)-51.37, where ${\mathit{Z}}_{\mathit{d}}$ is the charge number of the daughter nucleus and ${\mathit{Q}}_{\mathrm{\alpha }}$ is expressed in units of MeV. This behavior also numerically comes out of the semiclassical WKB calculation of the barrier penetration factor. The fine structure in the ratio of experiment over theory is briefly discussed.

Data are gathered to put to the test of a prediction of the single j shell model, that for selected nuclei the excitation energy of the double isobaric analog state in an even-even nucleus is twice the excitation energy of the single analog state in the adjacent even-odd nucleus. This two-to-one relationship works much better than one would expect. The effects of configuration mixing and the Coulomb interaction are considered.

Based on a Boltzmann equation, the transverse momentum distributions are calculated for central ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$${+}^{51}$V collisions with an aim to determine the in-medium nucleon-nucleon cross section. Indeed, the calculations suggest that measurements of the energy of balance, ${\mathit{E}}_{\mathrm{bal}}$, can provide a powerful tool to pin down the in-medium nucleon-nucleon cross section. Within our improved Boltzmann-Uehling-Uhlenbeck (BUU) model, the in-medium nucleon-nucleon cross section is narrowed down to ${\mathrm{\sigma }}_{\mathit{N}\mathit{N}}$≊30–40 mb, for the first time, using recent experimental data.

Exploiting the concept of F spin to link extended series of noncontiguous nuclei, it is proposed that F-spin multiplets (F=4.5, 5, and 5.5, respectively) commencing with ${}_{}{}^{158,160,162}{}_{}{}^{}$ Yb comprise series of nuclei with similar character resembling the O(6) dynamical symmetry or, at least, the γ-soft O(5) subgroup. The evidence brought to bear on this stems from the yrast ground band levels, B(E2) values, and signature effects in medium-spin negative-parity levels.

Pion-rho-exchange nucleon-nucleon potentials are derived for one or two Δ isobars in the intermediate states. As in the companion work on two-pion exchange, strong dynamical pair suppression is assumed. At the NNπ, ρ and NΔπ, ρ vertices Gaussian form factors are incorporated into the relativistic two-body framework by using a dispersion representation for the π- and ρ-exchange amplitudes. The Fourier transformations are performed using factorization techniques for the energy denominators, taking into account the mass difference between the nucleon and the Δ isobar. The potentials are calculated in the adiabatic approximation of all planar and crossed three-dimensional momentum-space πρ diagrams. We also give the contributions of the πρ iteration, which can be subtracted or not, depending on whether one performs a coupled-channel calculation for, e.g., the NN, NΔ system, or a single NN-channel calculation.

The πNN system is studied with two-term potentials for the πN interaction in the ${\mathit{P}}_{33}$ and ${\mathit{P}}_{11}$ channels. Such model systematics as the difference in the dominant πN ${\mathit{P}}_{33}$ input, the effect of the so-called backward propagating pion, the choice of the relative momenta (magic vectors) at the isobar vertices, etc., are investigated. The results in the πd-πd, πd-NN, and NN-NN reactions at intermediate energies are compared with the available experimental data. The overall quality of the predictions by the present approach is roughly comparable to that based upon the one-term ${\mathit{P}}_{33}$ isobar model supplemented by an appropriate ad hoc off-shell modification, but with a significant improvement in the description of the πd-NN asymmetry ${\mathit{A}}_{\mathit{y}0}$.

Evidence for collective behavior in the high-spin region of lead nuclei is provided by the observation of two collective structures in ${}_{}{}^{197}{}_{}{}^{}\mathrm{Pb}$. One of these bands is interpreted as an oblate collective structure built on oblate proton and possibly neutron states. A second more irregular band is suggested to be most likely a triaxial rotational band. Neutron and proton configurations for these bands are suggested from the results of quasiparticle Routhians and total Routhians surface calculations. A partial level scheme up to I≊69/2 and ${\mathit{E}}_{\mathit{x}}$≊8 MeV is presented.

The ${}_{}{}^{45}{}_{}{}^{}\mathrm{Sc}$(d,p) reaction has been studied at 12 MeV with an overall energy resolution of ∼15 keV. The energy levels in ${}_{}{}^{46}{}_{}{}^{}\mathrm{Sc}$ are obtained up to ${\mathit{E}}_{\mathit{x}}$∼7 MeV and the angular distributions are measured for most of the levels. The data have been analyzed in terms of the nonlocal finite range distorted-wave Born approximation method and l values and spectroscopic factors are derived.

We study the n+A→(A’${\mathrm{\pi }}_{\mathit{b}}^{\mathrm{-}}$)→n+A reaction, or resonant formation of pionic atoms, with neutron scattering. We evaluate the contribution of the interference of this reaction channel in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ to the elastic scattering amplitude at backward angles. The ratio of signal to the background at 80° is about ${10}^{\mathrm{-}3}$, and we estimate that the ratio does not improve at higher angles, hence making this reaction impractical. Our findings have repercussions on a similar reaction now running at the Indiana University Cyclotron Facility.

We consider intrinsic states of highly deformed nuclei in the framework of the universal Woods-Saxon model and show that valence nucleons in abnormal-parity high-j states contribute ∼20% to the electric quadrupole moments of these nuclei. Similarly, we show that in the single-shell asymptotic Nilsson model this contribution is ∼25% if reasonable effective charges are employed. We discuss, at some length, procedures used to arrive at reasonable effective charges. Both models reproduce the measured B(E2;$0_1^{+}$→$2_1^{+}$) values in the rare-earth and actinide regions without the need for normalization constants. No support is found for the assumption made in the pseudo-SU(3) and the fermion dynamic symmetry models that valence nucleons in abnormal-parity high-j states do not contribute to deformation. This counterintuitive assumption leads to an underestimate of the B(E2;$0_1^{+}$→$2_1^{+}$) values, which is compensated in these models by the use of appropriate normalization constants. Once the magnitudes are fixed, both models do correctly reproduce the B(E2) trends.