Medium- and high-spin band structure of the chiral candidate 132La

Medium- and high-spin states of La-132 have been studied based on the data obtained from Mo-100(S-36, p3n) and Cd-116(Na-23, alpha 3n) fusion-evaporation reactions using the EUROBALL and Gammasphere detector arrays, respectively. Triple-gamma coincidence relations, angular correlations, and linear polarizations of the observed gamma transitions have been deduced. The level scheme of La-132 has been considerably extended, and unambiguous spin and parity values have been assigned to most of the excited states. The configuration of one of the bands is pi g(7/2)(h(11/2))(2)nu h(11/2) instead of the previously thought pi h(11/2)nu h(11/2); thus its previously suggested magnetic rotational character cannot be upheld. The observed similarities between the level structures of La-132 and Pr-134 suggest the possible existence of a third pi h(11/2)nu h(11/2) band in La-132 that may show chiral features

Hindered gamow-teller decay to the odd-odd N=Z Ga 62: Absence of proton-neutron T=0 condensate in A=62

Search for a new kind of superfluidity built on collective proton-neutron pairs with aligned spin is performed studying the Gamow-Teller decay of the T=1, Jπ=0+ ground state of Ge62 into excited states of the odd-odd N=Z nucleus Ga62. The experiment is performed at GSI Helmholtzzentrum für Schwerionenforschung with the Ge62 ions selected by the fragment separator and implanted in a stack of Si-strip detectors, surrounded by the RISING Ge array. A half-life of T1/2=82.9(14) ms is measured for the Ge62 ground state. Six excited states of Ga62, populated below 2.5 MeV through Gamow-Teller transitions, are identified. Individual Gamow-Teller transition strengths agree well with theoretical predictions of the interacting shell model and the quasiparticle random phase approximation. The absence of any sizable low-lying Gamow-Teller strength in the reported beta-decay experiment supports the hypothesis of a negligible role of coherent T=0 proton-neutron correlations in Ga62