Structure of odd-odd Sb nuclei

Abstract

The structure of112,114,116,118Sb nuclei was studied with complex γ and electron spectroscopic methods via (p, nγ) and also (α,nγ) reactions (in the case of116Sb,118Sb)at 5.5–9.2 MeV proton and 14.5–16.0 MeV α-particle energies. New level schemes have been deduced. The energy splitting of the proton-neutron multiplet states of116,118,120,122,124Sb was calculated on the basis of the “parabolic rule”. Manyp−n multiplet states have been identified and conclusions have been drawn on the applicability of the parabolic rule as a simple guideline for experimental investigations. Detailed description of the energy spectra and electromagnetic properties of116,118,120,122,124Sb nuclei is given on the basis of the interactingboson-fermion-fermion/ odd-odd truncated quadrupole phonon model (IBFFM/OTQM). The calculations give account both of the “regular” and “irregular” behaviour of the energy splitting of thep−n multiplets, as well as of the electromagnetic moments, γ-branching and γ-mixing ratios. Conclusions have been drawn on the role of different interactions in the multiplet energy splitting. The IBFFM interpretation of the high-spin intruder bands and the spectroscopic factors of the neutron transfer reactions are also shortly discussed for Sb nuclei.