Isospin mixing at finite temperature in Zr-80

The degree of isospin mixing in the hot compound nucleus Zr-80 has been extracted by statistical-model analysis of the gamma-decay spectrum emitted in fusion reactions Ca-40+Ca-40 at E-beam= 200 MeV and Cl-37+Ca-44 at E-beam= 153 MeV. In the case of Ca-40+Ca-40 reaction an hindrance of first-step gamma-decay is expected because in self-conjugate nuclei the E1 selection rules forbid the decay between states with isospin I=0. The results obtained at finite temperature (T similar to 2 MeV) have been used to extrapolate the degree of mixing at zero temperature.