The polarized target asymmetry T(θ) for the reaction γd→pn has been measured at proton c.m. angles of 70°, 100°, and 130° in the photon energy region between 300 and 700 MeV. The observed asymmetry shows relatively small values. A phenomenological partial wave analysis is carried out by using the present T(θ) data together with recent results on the differential cross section dσ/dΩ, the recoil proton polarization P(θ), and the polarized beam asymmetry Σ(θ). The gross features of dσ/dΩ, T(θ), and Σ(θ) are reproduced reasonably well without dibaryon resonances, but those of P(θ) are not, even with arbitrary smooth backgrounds in the present scheme of analysis. Possible contributions of dibaryon resonances are studied.

The interacting boson model of nuclei is used to study 650 MeV proton scattering to the ${\mathit{J}}_{\mathit{i}}^{\mathrm{\pi }}$=$0_1^{+}$,$2_{1,3}^{+}$ state in ${}_{}{}^{154}{}_{}{}^{}\mathrm{Gd}$. All coupled channels within the interacting boson model space are included. The hadronic boson quadrupole operator is determined. Comparison with the electromagnetic boson quadrupole operator suggests that the $2_3^{+}$ state is not completely symmetric in the neutron and proton degrees of freedom.

The nucleon mass difference contribution to charge symmetry breaking in neutron-proton elastic scattering is calculated in a relativistic formalism based upon a covariant representation of the NN amplitude. The charge symmetry breaking amplitude is separated into two terms: a piece which involves the on-shell charge symmetric T matrix with charge symmetry breaking arising due to effects in external wave functions, and a term involving off-shell T matrices with charge symmetry breaking associated with mass difference effects in internal nucleon propagators. We find that most of the charge symmetry breaking arising from the neutron-proton mass difference comes from the latter term.

A model employing quark dynamics is applied to the ${\pi }^{\mathrm{-}}$+pp→pn reaction. Quark effects can provide a substantial contribution to the total absorption cross section, and qualitatively reproduce the measured angular distributions.

The electromagnetic vertex for an off-shell nucleon is investigated. To get an idea of the magnitude of the off-shell variation, which is usually neglected, a one-pion loop model is used. For simplicity, only the half-off-shell case is considered. Variations up to 10% relative to the on-shell case are found in the form factors for kinematics occurring in intermediate energy reactions. The magnitude of the off-shell effects is also investigated within a commonly used recipe for the electron-bound nucleon cross section and found to be of comparable size.

We investigate a new method of extracting nucleon form factors by using measured asymmetries of polarized leptons scattered off polarized targets. Systematic errors can be eliminated that way, unlike the conventional analysis via Rosenbluth plots. The kinematics can be chosen such that the asymmetry receives contributions selectively from either $G_M^2$($q^2$) or $G_E$($q^2$)$G_M$($q^2$). The latter combination allows a better determination of $G_M$($q^2$) for small $q^2$. We also discuss lepton mass effects in dσ/dΩ. While such mass effects reduce the suppression of magnetic contributions to dσ/dΩ for small $q^2$, they do not in general result in a greater sensitivity of dσ/dΩ or of the longitudinal asymmetries to a variation of the magnetic form factor, unless one chooses specific kinematics, as is demonstrated here. The transverse asymmetry, however, displays naturally a greater sensitivity to $G_M$($q^2$) for the muon as compared to the electron. Such experiments are feasible at both the electron facilities (Bates, CEBAF, MAMI, and ELSA) and the muon facilities (SIN, TRIUMF, and LAMPF). Constituent models of the nucleon (quark confinement models) emphasize the low -$q^2$ region of the form factors, where data presently are still incomplete. This has implications for the study of the nuclear response function in quasifree scattering (μ,μ’p) from nuclei using polarized muons.

Under certain conditions the asymmetry resulting from single charge exchange reactions arises only from the (quantum mechanical) distortion effects of the incoming and outgoing waves. If the distortion of the incident wave is well known, some basic properties of the hadronic interaction in the final state can be inferred. Examples for (${\pi }^{+}$,${\pi }^0$) and (${\pi }^{+}$,η) reactions are given.

The system of NN, NΔ, ΔΔ, and ${\mathrm{NN}}^{\mathrm{*}}$(1440) channels, coupled by long-range meson exchange forces and a short-range boundary condition, has been successfully applied to medium energy NN scattering. The deuteron system includes the NN${(}^3$${\mathit{S}}_1$, ${}_{}{}^3{}_{}{}^{}$${\mathit{D}}_1$), ΔΔ${(}^3$${\mathit{S}}_1$, ${}_{}{}^3{}_{}{}^{}$${\mathit{D}}_1$, ${}_{}{}^7{}_{}{}^{}$${\mathit{D}}_1$), and NN*${(}^3$${\mathit{S}}_1$) channels. The scattering data for nucleon $T_{\mathrm{lab}<1\mathrm{}}$ GeV put strong restrictions on the short-range parameters of the model, imposing ∼2% total isobar content in the deuteron, but do not determine the relative strength of coupling among the isobar channels. In contrast, the deuteron elastic magnetic form factor is sensitive to the mixture of isobars. Adding meson exchange current contributions, a good fit to these data can be achieved, including a nontrivial prediction of a minimum near $q^2$=50 ${\mathrm{fm}}^{\mathrm{-}2}$, by a balance between ΔΔ${(\mathrm{}}^3$$D_1$,${\mathrm{}}^7$$D_1$) components. Balancing ΔΔ${(\mathrm{}}^3$$S_1$,${\mathrm{}}^7$$D_1$) with ${\mathrm{NN}}^{\mathrm{*}}$${(\mathrm{}}^3$${\mathrm{S}}_1$), assuming a negative ${\mathrm{N}}^{\mathrm{*}}$ isoscalar magnetic moment, is only adequate for $q^2$<25 ${\mathrm{fm}}^{\mathrm{-}2}$. The static properties of the deuteron are well fitted, and the electric and tensor polarization form factors are consistent with the data. The inclusion of the lowest six-quark state, with cloudy bag model dynamics, increases the boundary radius, requiring ∼7% isobar content proportioned as above to approximately fit the data.

The cross sections for the pionic disintegration of the deuteron in the Δ-resonance region are calculated based on a unitary three-body model. The NΔ-NN transition potential is constructed from the πN $P_{11}$ and $P_{33}$ scattering amplitudes extrapolated to the off-shell region, and from the πNN three-body propagator. The idea of the two-potential model for the $P_{11}$ wave is extended to the $P_{33}$ wave. The parameters of the model are deduced from the fits to the πN scattering phase shifts. It is found that the off-shell $P_{11}$ and $P_{33}$ scattering amplitudes behave quite similarly to the monopole form factor with a cutoff momentum Λ=600 MeV/c as obtained earlier in the perturbation model by Gibbs, Gibson, and Stephenson. It is also found that the backward-propagating-pion component of the πNN propagator, which is often ignored in three-body calculations, is crucial to reproduce the magnitude of the total cross section. The three-body calculation is compared to the perturbation calculations. The second-order perturbation gives the results which closely approximate the full-order three-body calculation.

In the context of the quark exchange model of Lenz et al., effective hadron theories are constructed and the resulting physical observables compared to their ‘‘experimental’’ values as defined by the calculations using the exact quark model operators. This model study illustrates convergence issues for an effective hadron basis in a quark model in which all physical observables can be computed exactly.

The decay of radiochemically-separated ${}_{}{}^{228}{}_{}{}^{}\mathrm{Ac}$ sources has been reinvestigated using high-resolution coaxial HPGe detectors and γ-γ coincidence measurements. Energies and intensities of more than 240 photons were accurately measured, 80 of them for the first time. A ${}_{}{}^{228}{}_{}{}^{}\mathrm{Th}$ level scheme, built on the bases of good energy fits and on γ-γ coincidence data, involves 58 excited states, of which 17 are new, up to 2159 keV with spin 0≤I≤6. Collective properties of low-energy states belonging to $K^{\pi }$${=0\mathrm{}}^{\mathrm{-}}$,$2^{+}$,$2^{\mathrm{-}}$ bands are discussed in the framework of the Bohr-Mottelson model. Decay modes of a $K^{\pi }$${=0\mathrm{}}^{+}$ excited band at 831.82 keV favor strong two octupole phonon $K^{\pi }$${=0\mathrm{}}^{\mathrm{-}}$ components. The $K^{\pi }$${=1\mathrm{}}^{\mathrm{-}}$ band is expected to have I=2 and 3 members at 938.5 and 968.4 keV. Coriolis coupling calculations involving the four $K^{\pi }$${=0\mathrm{}}^{\mathrm{-}}$, $1^{\mathrm{-}}$, $2^{\mathrm{-}}$, and $3^{\mathrm{-}}$ bands were carried out. Tentative $K^{\pi }$${=2\mathrm{}}^{+}$ two-quasiparticle bands at 1638.23 and 1899.99 keV are discussed in terms of Nilsson orbitals.

The first and second excited $0^{+}$ states in ${}_{}{}^{122}{}_{}{}^{}\mathrm{Te}$ have been definitely identified as the 1357 and 1941 keV levels. Electric monopole transitions connecting the $0_3^{+}$, $0_2^{+}$, and $0_1^{+}$ states have been investigated by means of conversion electron and gamma spectroscopy. The ratios X(E0/E2) of reduced E0 and E2 transition probabilities have been determined. The experimental results are compared to the predictions of the neutron-proton interacting boson model.

Double ionization of the atomic K shell accompanying the K-shell internal conversion of the 0.166-MeV transition of ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}$ has been studied by recording triple coincidences between La K x rays, La K satellite x rays, and La Kα hypersatellite x rays emitted when the K-shell vacancies are filled. The probability per K-shell internal conversion that a double vacancy is formed, $P_{\mathrm{KK}}$(IC), was found to be (6.0±1.4)×${10}^{\mathrm{-}5}$, which is in good agreement with the K-shell electron shakeoff prediction of 5.1×${10}^{\mathrm{-}5}$ by Mukoyama and Shimizu.

A method for reconstructing low-spin rotational bands from deformed boson expansions developed in the first paper of this series is tested on a simple model. The model, a version of the Copenhagen-Frankfurt collective model, is treated by a boson expansion about a deformed mean-field approximation. The rotational band structure is then regenerated by the Marshalek-Weneser method. The results are compared with those of a more conventional treatment that preserves rotational invariance from the outset.

Temperature-dependent effects upon vibrational states are calculated within a finite temperature random phase approximation. Restoring force and mass parameters, calculated for a multipole-multipole interaction, are compared with liquid drop model values at nonzero temperature. Collective contributions to the level density parameter are discussed.

The neutron-deficient isotopes ${}_{}{}^{189\mathrm{-}194}{}_{}{}^{}\mathrm{Tl}$ have been studied using collinear fast atom beam laser spectroscopy with mass-separated beams of 7×${10}^4$ to 4×${10}^5$ atoms per second. By laser excitation of the 535 nm atomic transitions of atoms in the beam, the 6$s^2$7s ${}_{}{}^2{}_{}{}^{}S_{1/2}^{}{}_{}{}^{}$ and 6$s^2$6p ${}_{}{}^2{}_{}{}^{}P_{3/2}^{}{}_{}{}^{}$ hyperfine structures were measured, as were the isotope shifts of the 535 nm transitions. From these, the magnetic dipole moments, spectroscopic quadrupole moments, and isotopic changes in mean-square charge radii were deduced. A large isomer shift in ${}_{}{}^{193}{}_{}{}^{}\mathrm{Tl}$ was observed, implying a larger deformation in the ${(9/2\mathrm{}}^{\mathrm{-}}$ isomer than in the ${(1/2\mathrm{}}^{+}$ ground state. The ${}_{}{}^{189}{}_{}{}^{}$,191,193${\mathrm{Tl}}^{\mathrm{m}}$ isotopes have deformations that increase as the mass decreases. A deformed shell model calculation indicates that this increase in deformation can account for the drop in energy of the ${(9/2\mathrm{}}^{\mathrm{-}}$ bandhead in these isotopes. An increase in neutron pairing correlations, having opposite and compensating effects on the rotational moment of inertia, maintains the spacing of the levels in the ${(9/2\mathrm{}}^{\mathrm{-}}$ strong-coupled band. Results for ${}_{}{}^{194}{}_{}{}^{}\mathrm{Tl}_{}^{\mathrm{m}}{}_{}{}^{}$ differ from previously published values, but are consistent with the ${}_{}{}^{190}{}_{}{}^{}$,192${\mathrm{Tl}}^{\mathrm{m}}$ data.

A two-region model of the nuclear force is developed by using quark degrees of freedom at short ranges and nucleons elsewhere. In the quark sector, the soliton bag model and generator coordinates are used so that the quark fields undergo a continuous deformation as the two nucleons overlap. This model describes the spin singlet nucleon-nucleon scattering data very well. The density and binding energy of nuclear matter are also computed in lowest-order Brueckner theory. Quark effects are found to decrease both the saturation density and binding energy.

Values of B(E2) strengths connecting low-lying $0^{+}$ and $2^{+}$ states in ${}_{}{}^{70}{}_{}{}^{}$,72,74,76Ge are examined in the context of an earlier coexistence model previously applied to two-neutron transfer.

Ground-state properties of even-even nuclei in the s-d shell are calculated using relativistic mean-field models of baryon-meson dynamics that include scalar meson self couplings. Axial symmetry is assumed. The systematics of intrinsic quadrupole moments are studied for a variety of parameter sets that are fitted to the same nuclear matter saturation properties. The size of the moment is strongly correlated with the nucleon effective mass $M^{\mathrm{*}}$ and the spin-orbit strength, but is only weakly affected by the compressibility or the surface energy. If parameter sets with accurate spin-orbit strengths are used, the trends for s-d nuclei reproduce experimental systematics and are quantitatively similar to those obtained in nonrelativistic Skyrme-Hartree-Fock calculations. The implications for quantum hadrodynamics in the mean-field (Hartree) and one-loop approximations are discussed.

Excited positive parity states up to spin ((41/2) have been studied in ${}_{}{}^{77}{}_{}{}^{}\mathrm{Kr}$ using a 98 MeV ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ beam on a natural chromium target. ΔJ=1 transitions have been identified throughout the positive parity band. The energies, mixing ratios, and B(M1) transition rates for these transitions alternate in size as the spin increases. A cranked shell model analysis was performed along with Strutinsky-Bogolyubov cranking calculations. The observed decrease in the signature splitting of the ν$g_{9/2}$ band has been attributed to a band crossing due to an aligning pair of $g_{9/2}$ protons. Prolate quadrupole deformations of ${\beta }_2$=0.34 for the one-quasiparticle band and ${\beta }_2$=0.26 for the three-quasiparticle band are predicted. This band crossing is associated with a shape change caused by the polarization effect of aligned quasiparticles.