Structure of140Pm from beta decay of140Sm

Abstract

The structure of 14~ is investigated through the beta decay of ~4~ whose half-life is measured to be (14.7 + 0.2) m. A level structure comprising 41 transitions among 17 excited states is constructed. Using the deduced ft values and measured internal conversion coefficients, spin-parity assignments to several states in a*~ were made. From beta end-point measurement, the total decay energy is deduced to be QEc=3.4_+0.3 MeV, which is compared with the predictions of several mass formulae. The systematics of the odd-Z, N= 79 isotones are discussed.

Structure of N=81144Eu from the decay of144Gd

“…I.44 + lates high energy 1 states m Eu. Such 1 states have also been observed in other odd-odd nuclei of the same region (e. g. 14~ [3] and 142Eu [4]). Since the gamma deexcitation of these 1 + states proceeds through a variety of routes to the ground state, they cannot be assumed to have a simple structure.…”

High-spin states and collective band structures in the odd–odd140Pm nucleus

“…From the early β-decay measurements [25,26], spin and parity (I π ) of the ground state in 140 Pm has been assigned as 1 + . However, this state was not observed in the in-beam experiment [27].…”

“…In the N = 79 isotones, the high-spin states have been investigated extensively and many oblate bands have been identified in some nuclei [4,20,[22][23][24]. For 140 Pm, some level structures have been reported from β-decay and the 126 Te( 19 F, 5n) reaction in early reports [25,26], and then were reinvestigated with the 114 Cd( 30 Si, 1p3n) reaction [27,28]. However, contrasting to the neighboring nuclei, the information of high-spin states in 140 Pm is still lacking, and needs further study.…”