Fission yields for the ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zr}$ reaction at laboratory energies between 240 and 300 MeV have been measured. ‘‘Elastic scattering’’ angular distributions were also obtained and used to deduce the generalized total reaction cross sections. The competition between fission and light-particle evaporation from the compound nucleus is well reproduced by statistical-model calculations. However, the calculated neutron multiplicities for this reaction are larger than those previously measured. Possible reasons for this discrepancy are discussed.

The first data of elastic scattering of the unstable nucleus, ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ ($T_{1/2}$=53.3 d), are presented for a ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ target at 140 MeV. Secondary beams of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ were produced by using a polyethylene target with the reaction of ${}_{}{}^1{}_{}{}^{}\mathrm{H}$${(}^7$Li, ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$) at ${\theta }_{\mathrm{lab}=0\mathrm{}}$°. A magnetic spectrograph was used to focus ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ particles ejected from the polyethylene target onto a carbon target. The beam-spot size at the carbon target was less than 2 mm×2 mm. The energy resolution of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ beams was 1.6 MeV (full width at half maximum) with intensity of 2×${10}^4$ ${\mathrm{s}}^{\mathrm{-}1}$. Data were analyzed in terms of the double-folding model. It was found that a 25% reduction in the real-potential strength is required to fit the experimental cross section. Coupled-channel calculations demonstrated that such a reduction is due to the effect of projectile breakup.

A classical nonrelativistic microscopic model for high-energy heavy-ion collisions is presented, based on equations-of-motion calculations, where all the nucleon trajectories are computed with suitable two-body forces between all pairs of nucleons in the target and projectile. Comparison with experiment and with the results of other models is made. The model considers both position and velocity configurations according to a nuclear structure model, the isomorphic shell model previously and independently published. Thus, its results are objective and completely reproducible. The main feature, however, relies on the properties of the two-body potential used in the model which reproduces both the transverse momentum transfer cross section and the longitudinal momentum loss cross section, and at the same time possesses good saturation properties. While the present model uses a nonrelativistic approach, its results are comparable to those of other models using relativistic approaches.

The effect of the dynamic α-transfer polarization potential on several channels of the system ${}_{}{}^{24}{}_{}{}^{}\mathrm{O}$ has been calculated and compared to our experimental data and those of Paul and collaborators. The general agreement is good, indicating that the α-transfer coupling can have an important contribution to explain the back-angle anomalies observed in the elastic, inelastic, and transfer channels.

Recently acquired data on peripheral reactions induced by a ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ beam at 2.1 GeV/nucleon on a C target have been used to create a distribution of exclusive yields (‘‘mass patterns’’) in which the charge of detected fragments is ignored and the data supplemented by (presumed) missing nucleons. A simple multinomial expression using probabilities obtained from inclusive mass yields gives a satisfactory account of the revised data.

A nuclear projection model that produces generalized doorways in the sub-Coulomb region is used to calculate the modified structure factor S̃(E) in ${}_{}{}^{12}{}_{}{}^{}$C${+}^{12}$C down to about 3 MeV c.m. The formation of a compound nucleus is enhanced at energies near those of the generalized doorways which are obtained by coupling the shape resonances to the single and mutual excitation channels of the deformed ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ nuclei. The agreement between theory and experiment for S̃(E) in terms of magnitude and intermediate structure is dependent on the spreading width to complicated states as manifested in the energy averaging interval. The agreement in magnitude is striking in that the cross-section values are as small as ${10}^{\mathrm{-}3}$ mb at 3 MeV c.m. At low energies the nonresonant part of ${\sigma }_{\mathrm{comp}}$ is dominant, and the monotonic increase in S̃(E) with decreasing energy can be attributed to absorption under the barrier. Extrapolation of S̃(E) to the astrophysical energy of 1.7 MeV c.m. without a soft core suggests that the resonances will not introduce any dramatic structure. The presence of any prominent structure in this region may point to the need for a repulsive core in the nuclear potential.

Rotational bands in the odd-odd nuclei ${}_{}{}^{176}{}_{}{}^{}$,178Re have been studied via the fusion-evaporation reactions ${}_{}{}^{169}{}_{}{}^{}\mathrm{Tm}$${(}^{12}$,13C,xn). Several rotational bands have been identified for both isotopes. Techniques of gamma and internal conversion electron spectroscopy have been used. The different band structures are discussed in the frame of the two-quasiparticle-plus-rotor and cranking models.

The photofission cross section of Au was determined in the energy range 100–300 MeV by means of a quasimonochromatic photon beam. The nuclear fissility $P_f$ was calculated using the recently measured total photoabsorption cross sections. The nuclear excitation energy $E^{\mathrm{*}}$, charge and mass of compound nucleus were obtained by means of an intranuclear cascade Monte Carlo calculation. The fissility values determined for Au, Bi, and U were compared with the predictions of the cascade-evaporation model and remarkably fitted by the calculation.

A comparison of the penetrabilities calculated in the Wentzel-Kramers-Brillouin approximation through equivalent multihumped fission barriers shows that the penetrability saturates to its maximum value much more slowly for a three-humped potential than that for comparable two-humped and single-humped potentials. An analysis of the slopes of the near-barrier photofission cross sections of actinides yields results that can be understood in terms of the predicted potential barrier shapes for these nuclei, and thus provides evidence in support of resolving the ‘‘thorium anomaly’’ along the lines suggested by Möller and Nix. Our results further indicate that the uranium nuclei, and in particular ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$, may more likely exhibit three-humped potential shapes in which the apparent consequences of both the second and third minima may be observable.

The formation of hypernuclei through the photoproduction of kaons is formulated in the framework of a relativistic distorted wave impulse approximation. The basic production operator is based on diagrammatic techniques and includes low-lying baryon and meson resonances. Relativistic single-particle wave functions obtained by solving the Dirac equation with scalar and timelike vector potentials are employed to describe the nucleon and hyperon bound states. The nuclear and hypernuclear structure is described in a pure single-particle single-hole model. Evaluating the matrix elements in momentum space allows straightforward treatment of Fermi motion and naturally includes nonlocalities arising from the production operator. Different nonrelativistic limits involving the upper and lower component of the Dirac wave function and a p/M expansion of the operator are investigated. The final-state interaction of the weakly absorbed kaon is incorporated via an optical potential. A variety of angular distributions for p-shell nuclei is presented and the sensitivity of the hypernuclear cross sections to the elementary operator is shown to be important. Relativistic effects are found to be important along with effects of nonlocalities for low-spin states while high-spin states with large cross sections are less affected. Kaon distortion for p-shell nuclei only provides a slight reduction in cross section for most transitions.

Using the new experimental data on ${\mathrm{iT}}_{11}$, $T_{20}$, ${\tau }_{21}$, and ${\tau }_{22}$, presented in the first two parts of this work, along with existing differential cross section data, a helicity amplitude reconstruction of πd elastic scattering has been performed at $T_{\pi }$=256 and 294 MeV. Model-independent information has been obtained for the amplitudes ‖B‖, (‖A${\Vert }^2$+‖C${\Vert }^2$${)}^{1/2}$, ‖D‖, and the phase ${\phi }_D$. Taking two relations from a theoretical model in addition to the five existing observables, the seven real components of the πd helicity amplitudes have been determined. These amplitudes have then been used to calculate spin-transfer observables and the partial-wave components of the scattering amplitude.

A distorted wave impulse approximation formalism is described for (${\pi }^{+}$,2p) reactions. The reaction is assumed to proceed via absorption on a deuteron-like p-n pair projected from shell-model wave functions. The spin dependence of this primary interaction is assumed to be dominated by s-wave Δ-nucleon terms. Spin-orbit distortions of the emitted protons, and the coherent addition of different orbital angular momentum transfers, L, are properly taken into account. For L=2, the calculations show a significant dependence on the total angular momentum transfer, J${=1\mathrm{}}^{+}$, $2^{+}$, or $3^{+}$. These new calculations are compared with experimental data for the ${}_{}{}^{16}{}_{}{}^{}({\pi }^{+}$,2p${)}^{14}$N reaction.

As part of an experimental study of the nucleon-nucleon interaction at medium energy, the free neutron-proton analyzing power $A_n$(${\theta }_n^{\mathrm{*}}$,$T_n$) has been measured at nine incident neutron energies in the range 375≤$T_n$≤775 MeV and for neutron c.m. angles in the range 57°≤${\theta }_n^{\mathrm{*}}$≤159°. Unpolarized neutrons with a broad continuum of energies, produced by interaction of an 800 MeV proton beam with a beryllium target, were scattered from a polarized proton target. At each angle, for the whole energy region, the scattered neutron and conjugate recoil proton were detected in coincidence. A previously unseen minimum is observed in the energy dependence of $A_n$(${\theta }^{\mathrm{*}}$∼100°) near 625 MeV.

The first-order pion-nucleus optical potential is investigated in the nuclear surface including various corrections to the impulse approximation. The surface effects have been incorporated by performing a calculation for the semi-infinite nuclear matter in the coordinate space. The magnitude and the shape of the optical potential have been found to depend sensitively on the off-shell cutoff in the nuclear surface at low energies.

A comparison of the positron polarization from the decays of ${}_{}{}^{25}{}_{}{}^{}\mathrm{Al}$ and ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}_{}^{\mathrm{m}}{}_{}{}^{}$ is reported. A new instrument to perform these measurements has been installed on-line at a cyclotron and is described. The theoretical motivation for this experiment is discussed. Polarization data and results of systematic tests are reported. No difference in polarization was found at the level of 0.48%.

The beta-decay energy $Q_{\beta }$ of the neutron-rich chlorine isotopes ${}_{}{}^{40}{}_{}{}^{}$,42Cl produced by fragmentation of a tantalum target with a 2-μA proton beam has been determined. Energies of the beta transitions to bound levels in the daughter nuclei were measured by means of a scintillation telescope in singles or in coincidence with a high-efficiency Ge(Li) gamma counter. The ${}_{}{}^{40}{}_{}{}^{}\mathrm{Cl}$ and ${}_{}{}^{42}{}_{}{}^{}\mathrm{Cl}$ inferred experimental mass excesses, -27.72±0.08 and -24.66±0.22 MeV, respectively, are compared to mass predictions.

Samples of ${}_{}{}^{123}{}_{}{}^{}$,125Cd were obtained by on-line mass separator techniques applied to natural U fast-neutron fission products. Special emphasis was devoted to half-life measurements of the ${}_{}{}^{123}{}_{}{}^{}$,125Cd decays and to the level schemes of ${}_{}{}^{123}{}_{}{}^{}$,125In. Two half-lives of 2.12±0.03 s and 1.81±0.03 s have been measured for decays of ${}_{}{}^{123}{}_{}{}^{}\mathrm{Cd}$. Also, for decays of ${}_{}{}^{125}{}_{}{}^{}\mathrm{Cd}$ two half-lives of 0.68±0.04 s and 0.48±0.03 s were observed and measured. Four independent level schemes produced by the above-mentioned decays are proposed based upon the present results and previously reported data. The ${}_{}{}^{123}{}_{}{}^{}\mathrm{In}$ and ${}_{}{}^{125}{}_{}{}^{}\mathrm{In}$ level schemes are discussed within the hole-vibration coupling formalism, assuming a single hole coupled to the quadrupole surface vibrations of the corresponding ${}_{}{}^{124}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{126}{}_{}{}^{}\mathrm{Sn}$ isotopes. The interaction between the hole and the vibrating core is treated perturbatively within the nuclear field theory formalism.

Forward-angle cross sections for $1^{+}$ states have been measured in ${}_{}{}^{24}{}_{}{}^{}$,26Mg, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ by 201 MeV proton inelastic scattering. Comparisons are made with (γ,γ’), (e,e’), and (p,n) results. The measured strength is compared with microscopic distorted-wave Born approximation calculations using large-scale shell-model wave functions. Ratios of experimental to theoretical $1^{+}$ strengths are given. Almost no quenching is observed.

Cross sections for the elastic and inelastic scattering of monochromatic photons from ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ have been measured for incident photon energies between 17 and 28 MeV, spanning the region of the giant dipole resonance. The cross sections are interpreted in terms of the coupling between the giant dipole resonances built on the ground and $2_1^{+}$ states. A good quantitative description of the energy-averaged cross sections is obtained in the context of the dynamic collective model, provided ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ is a vibrational nucleus and ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ are prolate and oblate nuclei, respectively. The cross sections for ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ show considerable structure that is correlated in the elastic and $2_1^{+}$ channels and that is not predicted by the dynamic collective model. The elastic cross section is used to infer the total photoabsorption cross section, which is shown to be somewhat more structured than implied by previous direct measurements.

We solve the Bethe-Goldstone equation in nuclear matter for the scattering of a nucleon of a few hundred MeV. The angular momentum coupling caused by the nonspherical part of the Pauli blocking operator is treated exactly. It is found that standard approximation of angle averaging the Pauli operator is quite accurate for bulk properties of the reaction matrix even at energies as high as 300 MeV. Our result justifies one of the common approximations previously untested in the microscopic calculation of the optical model potential.