arXiv:nucl-ex/9502002·v1·Nuclear Experiment
High-K Isomers in 176W and Mechanisms of K-Violation
B. Crowell🇺🇸 · P. Chowdhury🇺🇸 · D.J. Blumenthal🇺🇸 · S.J. Freeman🇺🇸 · C.J. Lister🇺🇸 · M.P. Carpenter🇺🇸 · R.G. Henry🇺🇸 · R.V.F. Janssens🇺🇸 · T.L. Khoo🇺🇸 · T. Lauritsen🇺🇸 · Y. Liang🇺🇸 · F. Soramel🇺🇸 · I.G. Bearden🇺🇸
Abstract
An isomer, with t1/2 = 35 +- 10 ns and J, Kpi = 14, 14+, has been observed in the nucleus 176W using the reaction 150Nd(30Si,4n) at a beam energy of 133 MeV. The isomer exhibits an unusual pattern of decay in which the _majority_ of the flux proceeds directly to states with <K>=0, bypassing available levels of intermediate K. This severe breakdown of normal K-selection rules in 176W is compared with recent observations of K-violation in neighboring nuclei, within the framework of proposed theoretical approaches. The available data on these K-violating decays seem to have a consistent explanation in models of K-mixing which include large-amplitude fluctuations of the nuclear shape.
Comments: 47 pages, Latex; postscript figures available at http://www.phy.anl.gov/bgo/bc/w176/w176.html; submitted to Phys. Rev. C, 6 Feb 1995