Inelastic electron scattering cross sections have been measured from high spin transitions in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. Measurements were made over a range of momentum transfer of 1.1 to 2.9 ${\mathrm{fm}}^{\mathrm{-}1}$ with energy resolution between 14 and 22 keV. In addition to the previously measured ${14}^{\mathrm{-}}$, ${12}^{\mathrm{-}}$, and ${12}^{+}$ levels, electron scattering cross sections have been measured on M11, M10, M9, E9, and E7 transitions. High spin states are quenched from the predicted Woods-Saxon single particle amplitudes by 22% to 67%. Evidence is presented for the fragmentation of the 7.06 MeV ${12}^{\mathrm{-}}$ transition strength. Results are interpreted in terms of the independent particle model.

The double isovector giant dipole state has been observed in the (${\mathrm{\pi }}^{\mathrm{-}}$,${\mathrm{\pi }}^{+}$)Δ${\mathit{T}}_{\mathit{x}}$=+2 double-charge-exchange reaction on ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$, and ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}$. The resonances observed in the (${\mathrm{\pi }}^{\mathrm{-}}$,${\mathrm{\pi }}^{+}$) reaction are closely related via Coulomb displacement energy and isospin symmetry to the resonances measured in the inverse (${\mathrm{\pi }}^{+}$,${\mathrm{\pi }}^{\mathrm{-}}$) reaction on the same nuclei. The new observations provide a direct determination of the upper isospin component of the double giant dipole state, which is generally very weak in the (${\mathrm{\pi }}^{+}$,${\mathrm{\pi }}^{\mathrm{-}}$) reaction. The comparison between the double dipole in the two double-charge-exchange modes gives valuable information on the isospin splitting and the Pauli-blocking effects for isotensor transitions.

Electron conversion coefficients and γ-ray angular distributions for high spin states in ${}_{}{}^{128,129}{}_{}{}^{}\mathrm{La}$ are reported. Angular distribution information on ${}_{}{}^{129}{}_{}{}^{}\mathrm{La}$ shows that previously proposed spin assignments for the side band in this nucleus are incorrect. The ${}_{}{}^{128}{}_{}{}^{}\mathrm{La}$ electron conversion coefficients show that the observed dipole transitions have M1 multipolarities. The results are discussed in terms of a proposal that nuclei near ${}_{}{}^{128}{}_{}{}^{}\mathrm{Ba}$ are statically octupole deformed.

The level schemes of the isotones ${}_{}{}^{134}{}_{}{}^{}\mathrm{La}$ and ${}_{}{}^{136}{}_{}{}^{}\mathrm{Pr}$ were obtained with in-beam gamma spectroscopy techniques using fusion evaporation reactions with ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ beams and enriched targets of ${}_{}{}^{126,128}{}_{}{}^{}\mathrm{Te}$ and ${}_{}{}^{123}{}_{}{}^{}\mathrm{Sb}$. Rotational bands assigned to the π${\mathit{h}}_{11/2}$⊗ν${\mathit{h}}_{11/2}$ configuration were seen in both nuclei. Another band seen in ${}_{}{}^{136}{}_{}{}^{}\mathrm{Pr}$ was tentatively assigned to the π[413]5/2⊗ν${\mathit{h}}_{11/2}$ configuration. A beginning of a backbend seems to show up in this band.

The ${}_{}{}^{29}{}_{}{}^{}\mathrm{Si}$(p,γ), ${}_{}{}^{29}{}_{}{}^{}\mathrm{Si}$(p,${\mathit{p}}_1$γ), and ${}_{}{}^{29}{}_{}{}^{}\mathrm{Si}$(p,${\mathit{p}}_2$γ) reactions have been studied in the energy range ${\mathit{E}}_{\mathit{p}}$=2.025–3.310 MeV. Thirteen previously unknown resonances were observed, and γ-ray strengths were measured for 51 resonances. Elastic and inelastic scattering differential cross sections were measured near 23 resonances in the energy region ${\mathit{E}}_{\mathit{p}}$=0.94–3.32 MeV which had not been previously observed in elastic scattering. These measurements represent the first step in experiments to establish a complete level scheme for ${}_{}{}^{30}{}_{}{}^{}\mathrm{P}$ for the purpose of studying chaotic behavior in this system; the current state of knowledge of levels in ${}_{}{}^{30}{}_{}{}^{}\mathrm{P}$ is briefly discussed.

A quantum mechanical method of rotation and wobbling motion in triaxially deformed nuclei is represented within the framework of time-dependent Hartree-Fock theory. For such systems, the intrinsic frame is defined by imposing constraints of principal-axis frame. With aid of the canonical formulation of the constrained system, the Dirac quantization of the classical system is performed. It is shown that the commutation relations of angular momentum in the intrinsic frame then exactly satisfy the body-fixed frame. Furthermore, a method of describing large amplitude collective motion in the constrained system is proposed by extending the self-consistent collective-coordinate method.

The effects of core polarization on the single-particle energies and single-hole energies relative to a closed major shell core are considered. Not only the familiar two-particle–one-hole and three-particle– two-hole diagrams but also Hartree-Fock insertions are included. We further consider the effects of the Dirac spinor approach for nucleons inside the nucleus with a Dirac effective mass less than the bare mass and also for nucleons at the surface with an effective mass essentially equal to the bare mass. This relativistic effect tends to reduce the spin-orbit splitting of particle states as compared to that for hole states, which corresponds to the empirical data. The calculations are performed employing modern versions of the Bonn one-boson-exchange potentials with various strengths for the tensor component.

Nuclear rotational states are calculated in terms of a three-dimensional extension of the cranking model. A simple two-level model that allows for an exact solution is employed in the analysis. Various ways to define principal axes of the rotating nucleus are discussed. The minimal energy of the system corresponds to stationary rotational motion around a principal axis.

Within the framework of the Dirac-Brueckner (DB) approach, the properties of dense nuclear and neutron matter are investigated using realistic nucleon-nucleon (NN) interactions which are derived from relativistic meson-field theory and describe the two-nucleon system quantitatively. Single-particle potentials, equations of state, nucleon effective masses, Landau parameters, and speeds of sound are calculated and analyzed as functions of density, for both nuclear and neutron matter. In the DB approach, the equation of state comes out stiffer than in the most sophisticated nonrelativistic calculation, but softer than in the Walecka model. Possible extensions of the present approach to nucleon-nucleus scattering and nucleus-nucleus collisions are also discussed.

Two approaches to the microscopical derivation of the interacting boson model are examined and compared. The first one is the well-known Otsuka-Arima-Iachello method as extended to a multishell case by using the generalized seniority scheme or exact calculations in the seniority equal to 0 and 2 space. The second one is a procedure based on the similarity transformed Dyson mapping. Close agreement between the two approaches is found.

The systematics of the fission barrier shapes of a total of 47 doubly even actinide and transactinide nuclei have been studied using the double-humped fission barrier model. The fission barrier has been parametrized in terms of four smoothly joined parabolic segments. The penetrabilities through such double-humped fission barriers have been calculated in the Wentzel-Kramers-Brillouin approximation, and the various fission half-lives have been determined using the formalism given earlier by Nix and Walker. The various parameters of such fission barriers have been deduced by requiring their simultaneous consistency with the various relevant fission observables, namely, the near-barrier fission cross sections, isomeric energies and isomeric half-lives, where available, and the ground-state spontaneous fission half-lives in the region 90≤Z≤98, and such model calculations with some further justifiable asssumptions have been extended to the region of the still heavier nuclei with Z≥100. The results of our systematic study of the heights of the inner and the outer barriers of the double-humped fission barriers corresponding to such doubly even nuclei suggest that while the height of the inner barrier remains approximately constant in the entire region of such nuclei, the deduced heights of the outer barrier decrease rather sharply and continuously with the increase in the value of the fissility parameter until one reaches the element Rf (Z=104).

For the still heavier doubly even transactinides with Z=106 and 108, the deduced values of the height of the outer barrier remain approximately constant. Our deduced heights of the outer barrier for the various isotopes of a given element heavier than Pu also exhibit a maxima around the neutron number N=152, reflecting the experimentally observed extra stability in a similar variation of the ground-state spontaneous fission half-lives occurring presumably due to an apparent closure of a deformed subshell at N=152. This subshell effect is also found to disappear at Rf and for the heavier transactinide nuclei. While the various fission observables are reasonably reproduced in terms of a single set of fission barrier parameters for a given nucleus for most of the 47 doubly even actinide and transactinide nuclei considered in the present work, major difficulties remain for the odd-mass and for the doubly odd nuclei where the calculated ground-state spontaneous fission half-lives are found to be several orders of magnitude larger than those measured. Possible reasons for such discrepancies are briefly mentioned.

The polarization (P) and the analyzing power (A) were measured for the ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$(p,n${)}^{48}$Sc reaction at 135 MeV. Of special interest is the difference (P-A) in these two quantities for the transitions to the two $1^{+}$ states at 2.52 and 16.8 MeV. Because of the difference in the predominant one-particle–one-hole configurations for these two states, viz., (${\mathit{f}}_{7/2}$,${\mathit{f}}_{7/2}^{\mathrm{-}1}$) and (${\mathit{f}}_{5/2}$,${\mathit{f}}_{7/2}^{\mathrm{-}1}$), respectively, qualitative differences in P-A are predicted based on nonlocal exchange contributions. The experimental results agree qualitatively with these predicted differences, but there are significant quantitative differences indicating that other effects contribute as well.

Cross sections and the analyzing powers ${\mathit{A}}_{\mathit{y}}$, ${\mathit{A}}_{\mathit{y}\mathit{y}}$, and ${\mathit{A}}_{\mathit{x}\mathit{x}}$ for the ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zn}$(d${,}^6$Li${)}^{60}$Ni reaction forming the ground and first-excited states of ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$ are measured in 5° steps from ${\mathrm{\theta }}_{\mathrm{lab}}$=25° to 80° using a 16.4-MeV vector- and tensor-polarized deuteron beam. The ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ ground state and seven other states, each representing ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ continuum states of a given spin and internal orbital angular momentum, are included in finite-range, coupled-channel Born approximation (CCBA) calculations for ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zn}$(d${,}^6$Li${)}^{60}$Ni. The CCBA calculations demonstrate that α transfers forming these continuum states, particularly those forming the first $3^{+}$ state in ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, affect the ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zn}$(d${,}^6$Li${)}^{60}$Ni cross sections and analyzing powers strongly.

Results are presented for pion interferometry measurements of 1.8A GeV Ar+KCl and Ar+La, and 1.2A GeV Xe + La at the Lawrence Berkeley Laboratory Heavy Ion Spectrometer System. The parameters R, τ, λ, ${\mathit{R}}_{\mathrm{\perp }}$, and ${\mathit{R}}_{\mathrm{\parallel }}$ are presented for all three projectile-target combinations. The correlation between the extracted size of the pion source and the centrality of the collision is investigated as well as the freeze-out densities and the dependence of the source size on the mean momentum of the pion pairs. The experimental setup and analysis are discussed and comparisons made with the results of others. The phase space covered is at forward angles in the center-of-mass system.

The applicability of intermediate-energy heavy-ion charge-exchange reactions for measuring Gamow-Teller strength in nuclei is studied. A strong absorption model for such reactions is developed. Within the framework of this model, we define a sensitivity function which determines the important region of the target transition density in momentum space. It is found that the L=0 cross section provides a relatively model-independent measure of Gamow-Teller strength. An understanding of the large L=2 cross sections observed in heavy-ion-induced reactions is achieved. Specific application is made to the ${(}^{12}$C, ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$) reaction at E/A=70 MeV.

Capture-fission cross sections for ${}_{}{}^{40,48}{}_{}{}^{}\mathrm{Ca}$${+}^{197}$Au and ${}_{}{}^{40,48}{}_{}{}^{}\mathrm{Ca}$${+}^{208}$Pb have been measured at beam energies ranging from 195 to 416 MeV. The fissionlike fragments were detected in a pair of position-sensitive multiwire proportional counters and were identified from measurements of position and time using two-body kinematics. The data taken at energies above the barrier (up to 2.4 times the Coulomb barrier) were analyzed in terms of the extra push model showing a strong dependence on the Ca isotope. This dependence was also observed at energies below the barrier, where the results have been interpreted using a schematic coupled-channel code.

Direct breakup of ${}_{}{}^7{}_{}{}^{}\mathrm{\alpha }$+t was measured for 54-MeV ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$${+}^{12}$C, ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ reactions. The breakup products were detected in coincidence using a close-geometry detection system, and small scattering angles forward of grazing, were investigated. The direct-breakup cross sections for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ${(}^7$Li, αt${)}^{12}$${\mathrm{C}}_{\mathrm{g}.\mathrm{s}.\mathrm{}}$ exhibit significant enhancements beyond predictions of simple E1 Coulomb-breakup calculations, indicating the importance of the nuclear field. Direct-breakup yields in ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$${(}^7$Li,αt) quasielastic reactions are sensitive to detector geometry, with the asymptotic fragment energies exhibiting target-proximity effects. Three-body classical trajectory calculations are found to provide qualitative agreement with these observations, provided the projectile is treated as an extended object. These strong Coulomb and nuclear effects severely complicate the extraction of radiative-capture cross sections and low-energy astrophysical S factors.

Based on a two-nucleon model, we have studied the core polarization effects in near-threshold pion-production reactions ${}_{}{}^{12,14}{}_{}{}^{}\mathrm{C}$(p→,${\mathrm{\pi }}^{\mathrm{-}}$) ${}_{}{}^{13,15}{}_{}{}^{}\mathrm{O}_{\mathrm{g}.\mathrm{s}.\mathrm{}}^{}{}_{}{}^{}$. The core polarization reduces the absolute value of the pion-production cross section over all angular directions, while the analyzing power distributions are quite insensitive to it.

Various equivalent local potentials and their Perey factors are discussed. The Wronskian and inversion-type equivalent local potentials for the energy dependent nonlocal interaction induced by the coupling of the elastic to the nonelastic channels are investigated numerically. Their Perey factors are found to be closer to unity than those associated with exchange-type nonlocal potentials.

Elastic scattering of deuterons from ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ in the energy range ${\mathit{E}}_{\mathit{d}}$=9 to 79.2 MeV is analyzed using a dispersive optical model potential (OMP). In this analysis, a dispersion relation connects the volume integrals of the imaginary and the real parts of the OMP. Best-fit dispersive OMP parameters are obtained from fits to experimental cross-section and analyzing power data at one energy, and dispersive OMP parameters with a smooth energy dependence are determined from fits to the entire data set. Comparisons, showing fits of similar quality, of the predictions of the cross sections and analyzing powers given by the best-fit dispersive OMP and standard OMP are presented. Dispersive OMP parameters with a smooth energy dependence also give a good description of the experimental data.