Exclusive measurement of isospin mixing at high temperature in 32S

Abstract

Exclusive measurement of isospin (I) mixing in 32S at high temperature (T) has been performed utilizing the γ-decay of isovector giant dipole resonance (IVGDR). The degree of isospin mixing was deduced from the ratio of high energy γ-ray cross-sections of 32S and 31P populated at the same temperature and angular momentum (J). Precise temperature was determined by simultaneous measurement of nuclear level density (NLD) parameter and angular momentum. The measured Coulomb spreading width (Γ↓) seems to be independent of temperature and angular momentum. The isospin becomes a good quantum number with increase in temperature. However, when compared with the calculation at high temperature, measured isospin mixing is underpredicted by the calculations. Keywords: Isospin mixing in nuclei, Isovector giant dipole resonance, Statistical theory of nucleus, BaF2 detectors