Table of contents

Time-dependent Hartree-Fock calculations are presented using an approximation which decomposes the fully three-dimensional equations into a set of coupled equations in one and two dimensions. The approximation is tested for the alpha + alpha collision at a laboratory energy of 75.2 MeV and the extension of the technique to collisions of light and heavy nuclei is discussed.

Two-nucleon transfer data on ¹⁴C and ¹⁴N, and beta decay of ¹⁶C, to the lowest 1⁺ states of ¹⁶N are used to derive empirical wavefunctions.

Path-dependent phase factors for non-Abelian gauge theories are studied, in particular the differential and integral equations they satisfy and their transformation properties under the gauge group. As an illustration of its use, this work is applied to deriving the well known axial anomaly for a non-Abelian gauge theory, using a point-splitting method in which phase factors are inserted in such a way as to preserve gauge transformation properties at all stages of the regularisation procedure.

Evidence is presented for the existence of a pomeron flip-non-flip interference term in elastic polarisations. This might be understood to arise from absorptive corrections to a pomeron with small positive flip-non-flip ratio.

A simple model for the final-state interaction is formulated with an intermediate Delta in deuteron break-up induced by medium-energy hadrons. Since the Delta N system is close to threshold, only the S wave is considered and the Delta N interaction is treated using the multichannel K-matrix approach in the effective-range approximation. The rough features of the experimental data for the reactions pD to npp and K⁺D to K⁰* pp are reproduced.

The consequences of momentum and quantum-number conservation for multiparticle production are investigated at different energies. A simple independent emission model is constructed which describes data at both large p_T and average p_T. This enables features of large-p_T data such as the rise with energy of the spectrum and the 'jet-like' nature of events to be related to the need to conserve energy-momentum.

High spin states in ⁴²Ca have been excited with the ³⁹K( alpha ,p)⁴²Ca reaction at bombarding energies of 9.5 MeV and 16.0 MeV. Levels at 5491, 5744, 6145, 6409, 6554 and 7369 keV were shown to have J^pi of 6^-, 7^-, 7^(-), 8^-, 9^- and 10^-(8^-) respectively. Lifetimes for the 5491, 5744 and 6145 keV levels were determined to be 85+or-20 fs, 600+or-140 fs and <100 fs respectively. Multipole mixing ratios were deduced.

High-spin states in ¹⁷²W, ¹⁷⁴W and ¹⁷⁶W have been studied using gamma -ray techniques following (¹⁶O, xn) reactions on enriched Dy targets. The ground-state band has been shown to backbend in ¹⁷⁴W and ¹⁷⁵W, but not in ¹⁷²W. Side-bands are populated in each nucleus, with preferential population of an odd-spin sequence in each case. The decay properties of these bands, which have negative parity, suggest that they are due to the partial decoupling of a pair of quasi-particles by the Coriolis force. The properties of the bands are used to estimate in an empirical way the properties of a rotation-aligned (i₁₃2/)² neutron band in order to predict the systematics of backbending due to bandcrossing.

Deformation energy surfaces at very high spins of the nuclei in 'spherical' (Te-Sm) and transuranic (Po-Th) regions are calculated as a function of beta and gamma deformations in terms of the Strutinsky approach using the Woods-Saxon single-particle potential. In general, it is found that the nuclei in the 'spherical' region have the deepest energy minimum in the deformation energy surface at gamma =-60 degrees (oblate shape rotating around its symmetry axis) over a wide range of angular momenta (I approximately=30-70 h(cross)). The transuranic nuclei show a sudden change of their shape from nearly spherical to large prolate deformation.

The ⁶²Ni( alpha ,n gamma )⁶⁵Zn reaction has been studied at bombarding energies from 8.0 to 14.0 MeV. Angular distributions, linear polarisations and yield curves have been measured for transitions arising from odd-parity states with excitation energies up to about 2 MeV. Gamma-gamma coincidence measurements have been carried out. The Doppler-shift attenuation method has been applied to determine the lifetimes of the levels, and branching ratios, mixing ratios and transition rates have been deduced for the various gamma rays. Two transitions, not previously reported, have been found. Angular momenta and parities have been determined for all the states discussed. The predictions of the phonon-quasiparticle-coupling and shell models have been compared with the experimental results and found to be in reasonably good agreement.

The neutron-capture cross sections for all the stable even-A isotopes of Cd were measured with high-energy resolution ( Delta E/E<or approximately=0.2%), between 3 and 90 keV neutron energy at the 40 m station of ORELA. Average neutron-resonance parameters were evaluated and differ from previously accepted values. Both s- and p-wave radiative widths decrease strongly between ¹⁰⁶Cd and ¹¹⁶Cd as the neutron binding energy decreases. The average p-wave radiative widths are greater than the s-wave radiative widths for all isotopes. This is interpreted in terms of the configurations of the low-lying states. Both s- and p-wave neutron strength functions decrease as neutron number increases. This behaviour is attributed to an isospin term in the absorptive part of the optical-model potential.

Recent data by Gentry et al. (1976) presenting evidence of a superheavy element Z=126 might have included a component arising from proton-induced single-photon emission from rubidium, an element normally found in high concentrations in a mica environment. A classical calculation of the ratio of the single to double X-ray emission, however, suggests that the ratio for this case may be two orders of magnitude smaller than that observed recently in heavy-ion-induced X-ray experiments. The present results indicate that the ratio is indeed very much reduced, and that the contribution of single-proton emission process to the data of Gentry et al. cannot have been significant.