Restoration of the natural E(1/2+) - E(3/2+) energy splitting in odd-K isotopes towards N = 40
Restoration of the natural E(1/2+) - E(3/2+) energy splitting in odd-K isotopes towards N = 40
复制标题
恢复奇数 K 同位素的自然 E(1/2 ) - E(3/2 ) 能量分裂至 N = 40
DOI：
10.1016/j.physletb.2020.135215
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发表时间：
2020
影响因子：
4.4
通讯作者：
et al.
中科院分区：
文献类型：
--
作者：
Sun Y.L.;Obertelli A.;Doornenbal P.;Kondo Y.;et al.
本文报道了~（52，54）Ca（p，2 p）反应产生的~（51，53）K的首次γ能谱。通过使用一种基于反应顶点跟踪结合厚液氢靶的新技术，实现了光束强度下降到每秒几个粒子的非ambiibilian最终状态角动量分配。通过γ能谱和排他性的平行动量分布分析，建立了51，53 K下的32+基态和1/2+第一激发态，量化了在N= 32和34下恢复的1 d 32和2 s 1/2质子空穴态的自然有序性.最先进的从头计算和壳模型计算与改进的唯象有效相互作用再现目前的数据，并一致地预测增加的E（1/2 1+）-E（3/2 1+）的能量差向N= 40。
We report on the first γ-ray spectroscopy of 51, 53 K produced via the 52, 54 Ca (p, 2p) reactions at∼ 250 MeV/nucleon. Unambiguous final-state angular-momentum assignments were achieved for beam intensities down to few particles per second by using a new technique based on reaction vertex tracking combined with a thick liquid-hydrogen target. Through γ-ray spectroscopy and exclusive parallel momentum distribution analysis, 3/2+ ground states and 1/2+ first excited states in 51, 53 K were established quantifying the natural ordering of the 1 d 3/2 and 2 s 1/2 proton-hole states that are restored at N= 32 and 34. State-of-the-art ab initio calculations and shell-model calculations with improved phenomenological effective interactions reproduce the present data and predict consistently the increase of the E (1/2 1+)-E (3/2 1+) energy differences towards N= 40.