Shape mixing in sup(184,186)Hg

Recent potential energy calculations on even Hg isotopes have shown that sup(184,186)Hg are possibly deformed with two energy minima one each for oblate (β2=-0.14) and prolate (β2=0.28) shapes. The quasi-rotational levels in these nuclei have been studied by heavy ion reactions at Berley and Chalk River. The salient features of these studies are: a deviation of the energy levels from a rotational sequence for I <= 6; the levels with higher spins showing a good rotational spectrum and the deviation of the 4+→2+ and 2+→0+, E2 transition rates from the rotational value with β2=0.28. These features of the spectra are explained on the basis of mixing of bands based on the oblate and prolate shapes. The results of a simple band mixing calculation are presented and they reproduce the observed level spacings and B(E2) values. (author)