High-resolution measurement of the {sup 118,124}Sn(p,t){sup 116,122}Sn reactions: Shell-model and microscopic distorted-wave Born approximation calculations

The {sup 118,124}Sn(p,t){sup 116,122}Sn reactions have been investigated in high-resolution experiments at incident proton energies of 24.6 and 25 MeV, respectively. Angular distributions for 55 transitions to levels of {sup 116}Sn and 63 transitions to levels of {sup 122}Sn, up to excitation energies of {approx}3.850 and {approx}4.000 MeV, respectively, have been measured. The spin and parity identification was carried out by means of a distorted-wave Born approximation (DWBA) analysis, performed by using conventional Woods-Saxon potentials. A shell-model study of {sup 116}Sn and {sup 122}Sn nuclei was performed using a realistic two-body effective interaction derived from the CD-Bonn nucleon-nucleon potential. The doubly magic nucleus {sup 132}Sn was assumed as a closed core, with the 16 and 10 valence neutron holes occupying the five levels of the 50-82 shell. The energy spectra have been calculated and compared with the experimental ones, and the theoretical two-nucleon spectroscopic amplitudes, evaluated in a truncated seniority space, have been used in the microscopic DWBA calculation of some cross-section angular distributions of both reactions.