Yrast-state lifetimes in 94Pd at the transition between the isoscalar and isovector coupling regimes

초록

Half-lives of yrast excited states in 94Pd were measured using isomeric decay spectroscopy. The experiment was performed at Radioactive Isotope Beam Factory, where 94Pd ions were produced via in-flight fragmentation of a 124Xe beam impinging on a 9Be target. These ions were implanted into the GARi active stopper array, and isomeric delayed gamma rays were detected with the IDATEN fast-timing array consisting of 48 LaBr3(Ce) detectors. The half-lives were determined using the generalized centroid difference method, yielding the T1/2 values of 15 ps, 13(11) ps, 13 ps, 693(72) ps, and 19 ps for the (2+1 ), (4+1 ), (6+1 ), (8+1 ), and (10+1 ) states, respectively. Reduced transition probabilities were deduced from the measured half-lives and discussed in the context of shell-model calculations employing the JUN45 effective interaction. The results indicate that 94Pd, with N = Z + 2, lies in a transitional regime between the N = Z isoscalar-pairing domain (92Pd) and the N = 50 isovector-dominated region (96Pd).

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