No abstract available

[en] A search for a global optical potential for alpha-particles is described. It did not prove possible to find such a potential valid for a wide range of energies and nuclei, even treating the absorbing potential as an adjustable parameter for each nucleus. For practical purposes the best that can be done is to define an average potential, and such a potential is compared with a wide range of experimental data. Its energy variation is determined by fitting the total reaction cross-section. (author). 7 refs, 15 figs, 1 tab

[en] Level parameters for the 3⁺ doublet at about 19 MeV in ⁸Be are obtained from a two-level R-matrix fit to the ⁷Li+p ⁵P₃ phase shift, using the restrictions of the two-state isospin mixing model. The energy of the lower level is appreciably below the accepted value. Predicted contributions from the 3⁺ levels to the cross sections for the reactions ⁷Li(p,n), ⁷Li(p,γ), ¹⁰B(d,α) and ⁹Be(d,t) are compared with measured values, and qualitative agreement is obtained. The new values of the level parameters give agreement with values of the isospin mixing matrix element and of the excitation energy difference of the 3⁺, T=1 states in ⁸Li and ⁸Be, calculated assuming that the charge-dependent interaction is purely Coulomb

[en] An attempt is made to give a consistent account of observed properties of the low-lying levels of the mirror nuclei ¹³C and ¹³N. In the first stage of this analysis, least squares fits of the data are made using R-matrix formulae in the one- and two-level approximations; in the second stage, the resultant parameter values are compared with shell model predictions. Fitted properties include level widths, neutron scattering data, E1 radiative widths and E1 capture cross sections. The R-matrix formulae include external contributions to the E1 transition matrix elements, calculated using wavefunctions with the correct asymptotic forms. Acceptable fits are obtained for channel radii in the range 4-6 fm, with the lower values preferred. The parameter values obtained in these fits agree with shell model predictions, except for quantities involving the 3/2^- levels. Level displacement energies are calculated from the fitted parameter values. A reasonable account is given of two notable asymmetries between ¹³C and ¹³N-the very different excitation energies of the first excited states and the very different strengths of the E1 decays of these states

No abstract available

[en] A study has been made of the s-,-, d- and f-wave p-α scattering phase shifts up to a bombarding energy of 18 MeV, using a nonlocal separable interaction. Calculations have been made in the co-ordinate representation in which the Coulomb forces have been taken into account exactly. The separable-potential model of the nucleon-alpha interaction is found to be satisfactory

[en] It is suggested that measurement of the proton polarisation and analysing power for the elastic scattering ⁷Li(p,p)⁷Li should provide a sensitive test of time reversal invariance. It is possible that the 441 keV resonance could be a suitable energy region for study: alternatively measurements at higher energies and at selected angles should be suitable. (author)

[en] An attempt has been made to study the elastic scattering of protons using the optical model potential. The objective of the present work is to see how far the optical model accounts for light nuclear systems. p-³ He is a widely studied light nuclear system both theoretically and experimentally. The study has been carried out first with some of the existing global potentials and then to obtain a potential for the p-³ He system. Least squares searches were made at fixed geometry varying only depths of the there potentials U, W and V_so to obtain the minimum. The experimental cross section have been chosen at the energies of Ep =21.3, 35.0, 40.0 and 47.5 MeV which have good statistical accuracy. The data include both angular distributions and analyzing power in the elastic scattering taken over a wide angular range of about 10^o - 17^o. Reasonably good fits to the experimental data could be obtained using parameters, particularly for the angular distributions. The energy dependence of the central potential was found to be decreasing with the increasing energy expected. A linear relation has been obtained for the potential which agrees quite well with the experimental values. Similar behaviour is also found for the value integral of the real potential. 29 refs., 2 tables., 20 figs. (author)

[en] Elastic scattering of 65 MeV polarized protons from twenty five nuclei ranging from ¹⁶O to ²⁰⁹Bi have been analysed within the framework of the nine parameter optical model. A set of optical model parameters has been obtained which shows the systematic behaviour of the target mass dependence of the real potential, volume integral and the r.m.s. radius. The isotopic spin dependence of the real potential has also been studied. Parameters obtained by fitting the elastic scattering data have been able to reproduce the pickup and stripping reaction cross sections as studied in a few cases. (author)

[en] Angular distributions of 65 MeV protons from several nuclei over a wide range of mass and of 65 MeV neutrons from a few nuclei over the same range of mass are studied in terms of the local optical model using the surface absorption potential and systematics of the parameters are given. Several cases of inelastic scattering of protons are then studied and the corresponding deformation parameters are extracted. (author)