From the semiempirical formalism of Sood, energy levels of the $K^{\pi }$${=0\mathrm{}}^{+}$ ground state band in ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$, ${}_{}{}^{232\mathrm{-}238}{}_{}{}^{}\mathrm{U}$ even nuclei have been calculated. By ascribing appropriate values of N, better agreement is obtained with experimental data.

Using a Monte Carlo method, we study the energy efficiency of muon production by a high-energy beam of deuterons, i.e., protons and neutrons, injected into infinite deuterium-tritium targets. We present detailed results for the dependence on target density and beam energy. The key role of secondary (shower) production of muons is demonstrated. Constraints on the possibility of muon catalyzed fusion power reactors are established.

Angular and spectral distributions for the production of neutral subthreshold pions produced in nucleus-nucleus collisions are calculated by using a particle-hole formalism. The pions result from the formation and decay of the Δ(1232) resonance. Excellent agreement is obtained between theory and experiment.

The validity of Yukawa theories in nuclear physics is questioned beyond the mean-field approximation. It is shown that the large value of the meson-nucleon coupling constant puts an immediate upper bound on the relevant physical scale (about the nucleon mass) and this irrespective of the issue of renormalizability.

The iteration-subtraction method for the unified treatment of bound-state and scattering problems is compared and contrasted with a similar method for the two-body bound-state problem via nonsingular scattering equations developed recently. We also compare another recent method for solving bound-state problems with the iteration-subtraction method.

Semiclassical corrections to the optical potential for A=40 and A=120 are calculated in the second-order ħ expansion and compared with A=208. The corrections increase—as expected—with decreasing mass number. The optical potential is calculated by using the Hartree-Fock-Brueckner approximation for the determination of the effective two-body interaction.

A coupled channels calculation of the lowest lying positive parity bands of alpha particle cluster states in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ based on an ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$ core in its $0^{+}$ ground or $2^{+}$ first excited states is presented. The calculated energies and electromagnetic transition rates are in good agreement with the available experimental data, and it is suggested that analogous cluster states should be present in neighboring nuclei.

It is shown that a two-proton excitation model is able to explain the very striking changes observed in ‘‘α transfer reactions’’ to the $0^{+}$ levels of the Ge isotopes, when crossing the N=40⇆42 border line. The validity of a direct comparison between the populations of the $0^{+}$ levels of ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$ in the ${(}^6$Li,d) and in the ${(}^{16}$O, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$) reactions is critically discussed as well as the possible connection with our model.

The symmetry properties of low-lying eigenstates of $s$-shell nuclei are examined, and the lowest energy state is shown to be completely antisymmetric, which corresponds to the physical ground state. Green's function Monte Carlo methods may therefore be applied without the rapid increase in noise usually associated with fermion systems.

Comparison of the experimental and theoretical ground-state spins of odd-odd nuclei in the region $220\le A\le 228$ generally shows agreement with a folded Yukawa octupole deformed model with ${\epsilon }_3=0.08\mathrm{}$ and some lack of agreement with the same model with ${\epsilon }_3=0\mathrm{}$. Thus, in spite of limited spectroscopic information, the ground-state spins suggest the existence of octupole deformation in odd-odd nuclei in the region $220\le A\le 228$.

The states of ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ were studied by proton inelastic scattering at $E_{\mathrm{p}}$=65 MeV with an energy resolution of about 15 keV. The spectra obtained were highly structured and about 200 discrete levels were identified up to the excitation energy of 13.6 MeV. The widths of these levels were not noticeably wider than the instrumental energy resolution, even in the high excitation energy region above the neutron threshold. The values of transferred angular momentum L were assigned for most of the levels. The low-energy octupole resonance was observed as clustering L=3 states at the excitation energy between 7 and 12 MeV. In addition, many L=2 states and several L=0 states were observed above excitation energies of 10.5 and 12 MeV, respectively. These states are most likely the lower tails of giant quadrupole resonance and giant monopole resonance, respectively. Several unnatural parity states were clearly identified by comparing the (p,p’) spectra with (α,α’) spectra obtained at a few angles. The spin and parity of each of these states were assigned with the aid of microscopic distorted wave analysis. Several states prominent at backward angles were identified to be high-spin stretched or nearly stretched states.

An integral equation for a three-body continuum wave function is solved numerically in configuration space. The equation has a compact kernel. Knowing the breakup amplitude into three free particles, the asymptotic form for the breakup channel in configuration space can be studied. It turns out that the standard asymptotic form is achieved within a few percent only if the particles are separated by a few thousands of fm’s.

Angular distributions of the differential cross section and vector analyzing power have been measured for the ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$(d→${,}^3$He${)}^{205}$Tl reaction at an incident deuteron energy of 79.4 MeV. Spin-parity assignments have been made for seventeen transitions to residual nuclear states up to 2.8 MeV in excitation. Optical-model parameters have been obtained for both the entrance and exit channels by fitting elastic scattering data measured to large angles. Exact finite-range distorted-wave Born-approximation calculations have been performed and spectroscopic strengths have been deduced for all the observed transitions. The proton occupation numbers in ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ for 3$s_{1/2}$, 2$d_{3/2}$, 2$d_{5/2}$, and 1$h_{11/2}$ orbitals indicate a general depletion of about 30%, to be compared to 18% depletion previously reported in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. The 3$s_{1/2}$ proton occupation number in ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ deduced from this experiment is in good agreement with the results of recent (e,e’p) experiments.

The angular distributions of α particles for transitions to low lying states of ${}_{}{}^{141}{}_{}{}^{}\mathrm{Pr}$ in the ${}_{}{}^{144}{}_{}{}^{}\mathrm{Nd}$(p,α${)}^{141}$Pr reaction have been analyzed by assuming a coherent contribution from pickup and knockout. The importance of the knockout contribution is found to decrease substantially going from 25 to 35 MeV incident proton energy.

The (d,α) reaction has been studied with 79-MeV vector polarized deuterons on ${}_{}{}^{58}{}_{}{}^{}$,60,62,64Ni targets. Angular distributions of the differential cross section and vector analyzing power have been measured for strongly populated residual states in ${}_{}{}^{56}{}_{}{}^{}$,58,60,62Co up to an excitation energy of 5 MeV. The transferred orbital angular momenta L and total angular momenta J were determined from the characteristic shapes of the differential cross sections and vector analyzing powers yielding a number of new spin assignments. The $J^{\pi }$${=7\mathrm{}}^{+}$ stretched [(${\mathrm{Ni}}_{\mathrm{g}.\mathrm{s}.\mathrm{}}$${)}_{0+}$×(1${\mathit{f}}_{7/2}$${)}_{7,0}^{\mathrm{-}2}$] configuration states in the final nuclei were identified. Their location and their transition strength are used to test predictions from multiconfiguration shell-model calculations.

A semiclassical model developed for the computer simulation of nuclear reactions is applied to the problem of fragmentation in proton and heavy ion induced reactions. Simulations based on the model are used to follow the time evolution of the reactions in both coordinate and phase space as well as to calculate correlations for quantities such as fragment positions and masses. Three reactions are selected for detailed study: p+Ag at 300 MeV, and Ca+Ca at 25 and 50 MeV/nucleon bombarding energy. It is shown that the behavior expected for these reactions from the mechanical instability properties of nuclear matter is supported by the simulations. An experimental measure of the change from binary breakup to multifragmentation is shown to be the two-particle correlation function in mass.

The particle physics input to the NN charge asymmetric potential due to ρ-ω mixing is updated. The calculated changes in scattering lengths ‖$a_{\mathrm{nn}\mathrm{\Vert }\mathrm{-}\mathrm{\Vert }{a}_{\mathrm{pp}\mathrm{\Vert }\mathrm{\sim }1.3\pm 0.2}}$ fm are in good agreement with experiment (∼1.4±0.8 fm), as are the contributions to the binding energy difference in the A=3 mirror nuclei.

The ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$(p,n${)}^{32}$Cl reaction was studied at 135 MeV by the time-of-flight technique. The overall energy resolution obtained was about 270 keV. The forward-angle spectra are dominated by the excitation of $1^{+}$ states with characteristic ΔL=0 angular distributions peaked at 0°. The $1^{+}$ spectrum is described well by distorted-wave Born approximation calculations with full S-D shell-model wave functions and a normalization factor of 0.60. The strengths of the $1^{+}$ excitations are interpreted as being equivalent to Gamow-Teller strengths excited in beta decay. The (p,n) cross sections are converted to reduced transition probabilities, B(GT), by means of a ‘‘universal’’ relationship obtained from other nuclei where analog beta decay measurements are available. The general distribution and total strength so obtained are represented well by full S-D shell-model calculations with Gamow-Teller matrix elements adjusted to reproduce the strengths of Gamow-Teller beta decays of S-D shell nuclei. The $1^{+}$ (p,n) cross sections are interpreted also in terms of magnetic-dipole (M1) strength and compared with inelastic-electron scattering measurements of such strength in ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$. The strength observed in individual states is seen to vary considerably between the two reactions; these differences are ascribed to orbital-current contributions in the electron-scattering reaction not present in the (p,n) reaction. The (p,n) measurements extend to higher excitation energies than the electron-scattering measurements.

The ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$(α,n${)}^{16}$O and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$(α,α${)}^{13}$C reactions are investigated through the generator-coordinate method. Two bands with marked α${+\mathrm{}}^{13}$C structure are found in the ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ spectrum. Experimental candidates are proposed. The microscopic ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$(α,α${)}^{13}$C cross sections are in fair agreement with experimental data. We show that the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$(α,n${)}^{16}$O cross section at stellar energies is strongly affected by the 1/2 ${}_2{}^{+}{}_{}{}^{}$ (6.36 MeV) weakly bound state. The astrophysical S factor below $E_{\mathrm{c}.\mathrm{m}.\mathrm{}=0.3\mathrm{}}$ MeV is therefore significantly enhanced with respect to the extrapolations used for astrophysical purposes.

Transverse electron scattering form factors have been measured for isoscalar transitions to T=0 levels in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ at 1.37 MeV ($J^{\pi }$${=2\mathrm{}}^{+}$), 5.24 MeV ($3^{+}$), 6.01 MeV ($4^{+}$), and for the unresolved T=0 doublet at 4.12 MeV ($4^{+}$) and 4.24 MeV ($2^{+}$). Because of the large longitudinal form factors for these transitions, sometimes exceeding the transverse form factor by more than a factor of ${10}^4$, it was necessary to observe electrons scattered at 180° so that longitudinal scattering was minimized. Several incident energies from 80.1 to 200.5 MeV were used to span effective momentum transfers from 0.84 to 2.07 ${\mathrm{fm}}^{\mathrm{-}1}$. Results are compared with predictions calculated using Dirac wave functions for the nuclear bound states in a Woods-Saxon potential well.