Population of a low-spin positive-parity band from high-spin intruder states in 177Au: The two-state mixing effect.

The extremely neutron-deficient isotopes 177,179Au were studied by means of in-beam γ -ray spectroscopy. Specific tagging techniques, α -decay tagging in 177Au and isomer tagging in 179Au, were used for these studies. Feeding of positive-parity, nearly spherical states, which are associated with 2 d 3 / 2 and 3 s 1 / 2 proton-hole configurations, from the 1 i 13 / 2 proton-intruder configuration was observed in 177Au. Such a decay path has no precedent in odd-Au isotopes and it is explained by the effect of mixing of wave functions of the initial state. [ABSTRACT FROM AUTHOR]