The ${\mathit{K}}^{+}$${\mathrm{-}}^{12}$C and ${\mathit{K}}^{+}$-d cross sections and their ratios have been calculated microscopically using the ${\mathit{K}}^{+}$N Bonn interaction with density-dependent nucleon Dirac spinors. The density dependence leads to important effects and improves the agreement with the experimental data, even if the final results are very dependent on the Λ exchange term.

The relation between the kinematic and dynamic moments of inertia, ${\mathit{scrJ}}^{\mathrm{}\left(1\right)\mathrm{}}$ and ${\mathit{scrJ}}^{\mathrm{}\left(2\right)\mathrm{}}$, was analyzed for the normally deformed and superdeformed rotational bands. According to the ab expression for rotational spectrum, E(I)=a[ √1+bI(I+1) -1], the ratio R= √[${\mathit{scrJ}}^{\mathrm{}\left(1\right)\mathrm{}}$${]}^3$/${\mathit{scrJ}}^{\mathrm{}\left(2\right)\mathrm{}}$ should be I independent. Extensive analyses for the normally deformed rotational bands in the rare-earth and actinide nuclei show that the R’s do remain I independent. The same relation holds well for the superdeformed bands observed in the A∼190 region, and seems also to hold for those in the A∼150 region, if spin assignments are made correctly. The I independence of R provides an additional support to the spin assignments.

We consider the effect of strong-vertex form factors on the gauge invariance of Born diagrams for the pion photoproduction reaction. The minimal-substitution prescription of Ohta for the electromagnetic current operator in pion photoproduction yields the same result as the simplest Born approach for one particular invariant amplitude. This is incompatible with recipes that multiply the Born amplitude by an overall form factor.

We have studied the present theoretical understanding of size of neutron, proton, matter, and charge distributions in spherical nuclei. The ground-state nuclear radii have been evaluated in the framework of the relativistic mean-field approach within the Hartree approximation. A comparison has been done with the radii obtained with the nonrelativistic density-dependent Skyrme interactions. It is pointed out that with an increase in isospin of nuclei, the neutron rms radii in the relativistic mean-field approach are larger than both the empirical data and the predictions of the Skyrme mean field.

Nuclear matter at high density requires a relativistic description. Recent two-loop calculations in local quantum field theory models at finite density yield disastrously large contributions. We argue that the composite structure of nucleons ought to soften these contributions. This argument is supported by a model calculation in which we find very strong reductions in the Lamb shift and vacuum fluctuation contributions. At nuclear matter densities and beyond, the total-loop result is perturbatively small in comparison to the one-loop calculation.

A method is proposed for the analysis of pp-pp, πd-πd, and pp-πd processes concerning a narrow structure of KEK pp-${\mathit{A}}_{\mathit{y}}$ data (${\mathrm{\theta }}_{\mathit{c}}$≊39°) at √s ≃2.16 GeV. The analysis of these ${\mathit{A}}_{\mathit{y}}$ data, together with the Saclay pp dσ/dΩ(${\mathrm{\theta }}_{\mathit{c}}$=90°) data, indicates that the narrow structure can be explained by the structure of the ${}_{}{}^3{}_{}{}^{}$${\mathit{P}}_2$, ${}_{}{}^3{}_{}{}^{}$${\mathit{F}}_3$, or ${}_{}{}^3{}_{}{}^{}$${\mathit{H}}_5$ wave, while the structure in the ${}_{}{}^3{}_{}{}^{}$${\mathit{F}}_3$ or ${}_{}{}^3{}_{}{}^{}$${\mathit{H}}_5$ wave is more favorable than that in the ${}_{}{}^3{}_{}{}^{}$${\mathit{P}}_2$ wave. Furthermore, the analyses are extended to the other data on pp-pp, πd-πd, and pp-πd processes to restrict the solutions. Then the efficient observables for this purpose are proposed.

We calculate the proton-proton densities of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ using ground-state wave functions obtained from the Faddeev and Faddeev-Yakubovsky methods, respectively. The experimental ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ proton-proton momentum space density is extracted from the electric-charge form-factor data and the longitudinal Coulomb sum rule. We use this as a testing ground for coordinate space Faddeev wave functions based on different realistic nucleon-nucleon interactions, such as the Bonn, Paris, Argonne, Urbana, and SSC-C potentials. We find that the Paris potential reproduces the proton-proton density best, although it does not have sufficient repulsion to reproduce the first minimum. Upon Fourier transformation into coordinate space, we find that the proton-proton density data are not consistent with any of the realistic nucleon-nucleon interactions. With the Faddeev-Yakubovsky amplitudes for the ${}_{}{}^4{}_{}{}^{}\mathrm{He}_{\mathrm{g}.\mathrm{s}.\mathrm{}}^{}{}_{}{}^{}$ wave function and the SSC-C potential, the calculated proton-proton density is consistent with the data, which is, however, of poor quality. Recent (e,e’) data will help to provide the required refinements.

The sensitivity of the ppγ process to the different off-shell behaviors of existing nucleon-nucleon interactions based on modern potentials is investigated within a relativistic approach. We find that the analyzing power is sufficiently sensitive to distinguish between the off-shell behaviors of those interactions considered. The ppγ spin-correlation coefficients are also found to be sensitive to off-shell differences of nucleon-nucleon interactions so that, if data for these observables were available, they could be used to disentangle different off-shell nonequivalent interactions. The cross sections are unable to discriminate between those interactions considered based on their off-shell differences.

The Faddeev equations for three identical spinless particles in three-dimensional space interacting via harmonic-oscillator two-body potentials are solved analytically for any excitation and for an arbitrary value of the total angular momentum.

A theoretical description of the electron-induced three-body breakup process is presented. The continuum wave functions for three outgoing nucleons are determined exactly by solution of the Faddeev equations. A local s-wave spin-dependent potential, described by a separable form, is used as two-nucleon input. The response functions of the mirror three-body nuclei are calculated as a function of the energy transfer at momentum transfer values of 300, 400, and 500 MeV/c. It is in particular found that the predictions of the longitudinal response function are well in accordance with the experimenal data when the final-state interactions are taken into account.

Effects on the hadronic and electromagnetic properties of the two-nucleon system above pion threshold, arising from the interaction of the Δ isobar with nucleons, are investigated. The instantaneous nucleon-Δ potential is based on the meson exchange. Two-body reactions connecting channels with at most one pion and one photon are studied. Processes leading to a three-body pion-two-nucleon final state are considered in the restricted kinematic domain in which the pion forms the ${\mathit{P}}_{33}$ resonance with one of the nucleons. The nucleon-Δ potential is seen to increase the relative importance of the inelastic strength of two-nucleon spin-triplet states with respect to spin-singlet states, correcting a deficiency common in most existing models. Theoretical predictions are compared with recent experimental data for the various reactions. In particular, the differential cross section and the proton beam asymmetry for pp→n${\mathrm{\Delta }}^{++}$ (p${\mathrm{\pi }}^{+}$) are calculated, the latter observable being especially sensitive to the nucleon-Δ interaction.

For the problem of interaction between the lightest p+d, d${+}^3$He nuclei supermultiplet expansion of the reaction amplitude ${\mathit{T}}_{\mathit{L}\mathit{S}}$ is proposed. We have disclosed the nonpotential character of channels with S=1/2, where the scattering amplitude is written as a superposition of the potential amplitudes ${\mathit{T}}_{\mathit{L}}^{\left[\mathit{f}\right]}$ with different symmetries [f]. We have constructed the interaction potentials ${\mathit{V}}_{\mathit{L}}^{\left[\mathit{f}\right]}$, [f]=[21], [3] and [f]=[32], [41] for p+d and d${+}^3$He, respectively. The differential cross sections for p+d inelastic scattering with the deuteron spin-isospin flip, which correspond to the available experimental data in the low-energy region, are predicted at higher energies and also for the d${+}^3$He system in a broad energy interval. The potential-model approach well describes quantitatively the photonuclear ${}_{}{}^3{}_{}{}^{}\mathit{p}$+d and d${+}^3$He${\to }^5$Li γ processes in a broad photon energy range ${\mathit{E}}_{\gamma }$≤30 MeV.

It is shown that the Biedenharn-Blatt formula for the shape parameter for the coupled-channel case as an integral involving the zero-energy wave function actually gives the bar-shape parameter ${\mathit{P}}_{\mathit{b}}$ and not the eigenshape parameter ${\mathit{P}}_{\mathit{e}}$ as stated by the authors. We show that the zero-energy bar-wave functions and the zero-energy eigenwave functions are identical, and thus we obtain, by two different methods, the formula ${\mathit{P}}_{\mathit{b}}$-${\mathit{P}}_{\mathit{e}}$=${\mathit{q}}^2$/(${\mathit{a}}_{\mathit{t}}$${\mathit{r}}_0^3$), where ${\mathit{a}}_{\mathit{t}}$ is the triplet scattering length, ${\mathit{r}}_0$ the effective range, and q the energy derivative of the eigenmixing parameter at zero energy. The term ${\mathit{q}}^2$/(${\mathit{a}}_{\mathit{t}}$${\mathit{r}}_0^3$) results from the ${\mathit{k}}^2$ behavior of the eigenmixing parameter at low energies, the bar-mixing parameter having a ${\mathit{k}}^3$ dependence, and the order in which two particular limits are taken. We verify our new formula by considering potentials derived from the Reid hard-core potential model for the ${}_{}{}^3{}_{}{}^{}$${\mathit{S}}_{1\mathrm{-}}^3$${\mathit{D}}_1$ state of the neutron-proton system, with the tensor potential taken to have a variable strength.

Elastic and inelastic scattering of polarized protons, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ particles, and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ particles from ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$ and ${}_{}{}^{176}{}_{}{}^{}\mathrm{Yb}$ have been measured at the incident energy of 30 MeV/nucleon. Coupled-channels analyses have been performed using the deformed optical potentials (DOP’s) based on the symmetric rotational model. The quadrupole (${\mathit{Q}}_2$) moments of the real parts of the DOP’s for the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ scattering have been found to be larger than those of the charge distributions by about 5%. They are well explained by the folding model calculation with the density-dependent M3Y interaction. The ${\mathit{Q}}_2$ moments for the proton and the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ scattering are almost equal to or smaller than the charge quadrupole moments, and are not reproduced by the conventional folding model. These discrepancies suggest that there are other important reaction mechanisms not being explained in terms of the folding model with the effective interaction. For the proton scattering, the explicit coupled-channels calculations including neutron pickup channels are found to reduce largely the discrepancies in the ${\mathit{Q}}_2$ moments. Breakup channels are expected to give a significant contribution to the small ${\mathit{Q}}_2$ moments of the DOP’s for the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ scattering.

The gyromagnetic factors of yrast states in ${}_{}{}^{156,158}{}_{}{}^{}\mathrm{Gd}$ and ${}_{}{}^{166,168}{}_{}{}^{}\mathrm{Er}$, belonging to the ground-state rotational band, have been measured with the transient magnetic-field technique. Levels of interest were populated in charge exchange induced by a ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ beam. Mixed enriched isotope targets were employed in order to avoid systematic errors when comparing the results for the different isotopes. ${}_{}{}^{158}{}_{}{}^{}\mathrm{Gd}$ and ${}_{}{}^{168}{}_{}{}^{}\mathrm{Er}$ were used as internal calibration. In both ${}_{}{}^{156}{}_{}{}^{}\mathrm{Gd}$ and ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$ significantly smaller reduction of the g factor with increasing spin has been found than previously reported, in agreement with the predictions of cranked-shell-model and cranked Hartree-Fock-Bogouliubov calculations.

Measurements of inelastic electron cross sections from ${}_{}{}^{25}{}_{}{}^{}\mathrm{Mg}$ at a backward angle and in the energy range 120 to 260 MeV are analyzed, and transverse form-factors results for the two lowest excited levels of the fundamental band were extracted. This new information is compared with rotational model calculations, in which the collective current contributions are included in phenomenological ways and on more microscopic theoretical grounds. For the energy levels considered the overall agreement is good, although no clear distinction between the various approximations for the rotational current could be made with the presently available data.

High-spin states of the transitional nucleus ${}_{47}{}^{101}{}_{}{}^{}\mathrm{Ag}_{54}^{}{}_{}{}^{}$ have been studied up to spin J=41/2 with the reaction ${}_{}{}^{70}{}_{}{}^{}\mathrm{Ge}$${(}^{35}$Cl,2p2n), using γ-γ coincidence and γ-ray angular-distribution measurements. The low-spin states of this nucleus involve single-particle excitations, with little evidence of quadrupole collectivity. At high spins, a coupled band structure has been identified, consisting of a cascade of ΔJ=1 transitions with stretched E2 crossover transitions, similar to high-spin negative-parity bands observed in the heavier odd Ag nuclei. Detailed cranked Nilsson-Strutinski calculations are presented, which predict deformed rotational states based on configurations involving ν${\mathit{h}}_{11/2}$ excitations, and agree well with the energy levels of these high-spin negative-parity band structures. The changing nature of collectivity in these nuclei above the N=50 shell closure is discussed.

The ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$${(}^3$He,d${)}^{52}$Cr reaction has been studied at 15 MeV using the tandem Van de Graaff accelerator and the multichannel magnetic spectrograph of the Nuclear Physics Laboratory, Oxford. Angular distributions have been measured for levels up to ${\mathit{E}}_{\mathit{x}}$=8.6 MeV over the laboratory angular range θ=3.75°–71.25°. Data are analyzed in terms of the distorted wave Born approximation theory of the direct reaction. The l transfers and the spectroscopic factors are obtained.

Nuclear structure functions are extracted for high-energy electron scattering from nuclei at large values of the kinematic variable x and ${\mathit{Q}}^2$ in the range 1–4 (GeV/c${)}^2$. At the highest ${\mathit{Q}}^2$, the data for x>1 begin to display a scaling indicative of local duality.