Comparison of superdeformed bands in 61Zn and 60Zn: Possible evidence for Τ=0 pairing

The yrast superdeformed band in ⁶¹Zn has been established using ²⁸Si(³⁶Ar, 2pn)⁶¹Zn and ⁴⁰Ca(²⁹Si, 2α)⁶¹Zn fusion-evaporation reactions. The excitation energy of this band was determined via two transitions that link this band to the normally deformed states. Lifetime analysis of this band resulted in a quadrupole moment of Q1 = 3.0±^0.50.4e b, which corresponds to a deformation of β2 = 0.50±^0.070.06. A comparison of the J⁽²⁾ dynamical moments of inertia of the yrast superdeformed band in ⁶¹Zn with those in ⁶⁰Zn shows a nearly complete blocking of the observed alignment in ⁶⁰Zn, indicating that Τ = 0 proton-neutron pair correlations may be present in ⁶⁰Zn.