Ponente
Descripción
We propose for systematic measurement of low lying states and beta decay half-life of Ho-Yb-Hf isotopes in unknown region N~114-120 to study i) sudden shape change expected in N~114-118 ii) half-life at the edge r-process nuclei near N~120.
The Ho-Hf region is one of the least studied in the nuclear chart, where only lifetime up to N=110 is known in the case of Yb. The region of Yb presents a typical rotational structure R4/2~3.3 until 178Yb. The mean field calculations and IBM calculations expect the prolate shape in N <114 rapidly changes to oblate N>118 similar to heavier Pt, Os cases [Nomu11, Robl09, Yang21]. The recent mass measurement in 178Yb presented a sudden change in the systematics [Huan19], indicating a possible change in the structure much earlier than predicted. The systematic measurement of 2+ and 4+ states of Hf-Yb-Ho isotopes in this region through beta decay can shed light on the systematic shape evolution in this region.
The r-process and i-process network calculation studies [Mump16,24 and Deni21] indicate the region with a large impact as well as the highest uncertainty in beta-decay half-life abundance occurs in 118≤N≤126. The systematic measurement of half-life near N=120 can directly measure the beta-decay half-life in this high-impact region.
[Nomu11] K. Nomura et al., Phys. Rev. C 84, (2011) 054316
[Robl09] L.M. Robledo, R. Rodriguez-Guzman, P. Sarriguren, J. Phys. G 36, 115104 (2009)
[Yang21] X. Q. Yang et al., Phys. Rev. C 103 (2021) 054321
[Huan19]W. J. Huang et al., Eur. Phys. J. A, 55 (2019), 96
[Mump16,24]M. R. Mumpower et al., Prog. Part. Nucl. Phys. 86 (2016) 86 ;M. Mumpower et al., ApJ 970 (2024) 173
[Deni21] P. A. Denissenkov et al. MNRAS503, 3913–3925 (2021)
