Global properties of K hindrance probed by the γ decay of the warm rotating 174W nucleus


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Vandone V., Leoni S., Benzoni G., Blasi N., Bracco A., Brambilla S., ...Daha Fazla

Physical Review C - Nuclear Physics, cilt.88, sa.3, 2013 (SCI-Expanded) identifier identifier

Özet

The K hindrance to the γ decay is studied in the warm rotating 174W nucleus, focusing on the weakening of the selection rules of the K quantum number with increasing excitation energy. 174W was populated by the fusion reaction of 50Ti (at 217 MeV) on a 128Te target, and its γ decay was detected by the AGATA Demonstrator array coupled to a BaF2 multiplicity filter at Laboratori Nazionali di Legnaro of INFN. A fluctuation analysis of γ coincidence matrices gives a similar number of low-K and high-K discrete excited bands. The results are compared to simulations of the γ-decay flow based on a microscopic cranked shell model at finite temperature in which the K mixing is governed by the interplay of Coriolis force with the residual interaction. Agreement between simulations and experiment is obtained only by hindering the E1 decay between low-K and high-K bands by an amount compatible with that determined by spectroscopic studies of K isomers in the same mass region, with a similar trend with excitation energy. The work indicates that K mixing due to temperature effects may play a leading role for the entire body of discrete excited bands, which probes the onset region of K weakening. © 2013 American Physical Society.