$^{25}F$ 的核心与 $^{24}O_{基态}$ 的核心有多大差异？

How Different is the Core of ^{25}F from ^{24}O_{g.s.} ?

作者信息

Tang T L, Uesaka T, Kawase S, Beaumel D, Dozono M, Fujii T, Fukuda N, Fukunaga T, Galindo-Uribarri A, Hwang S H, Inabe N, Kameda D, Kawahara T, Kim W, Kisamori K, Kobayashi M, Kubo T, Kubota Y, Kusaka K, Lee C S, Maeda Y, Matsubara H, Michimasa S, Miya H, Noro T, Obertelli A, Ogata K, Ota S, Padilla-Rodal E, Sakaguchi S, Sakai H, Sasano M, Shimoura S, Stepanyan S S, Suzuki H, Takaki M, Takeda H, Tokieda H, Wakasa T, Wakui T, Yako K, Yanagisawa Y, Yasuda J, Yokoyama R, Yoshida K, Yoshida K, Zenihiro J

机构信息

Center for Nuclear Study, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.

RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.

出版信息

Phys Rev Lett. 2020 May 29;124(21):212502. doi: 10.1103/PhysRevLett.124.212502.

DOI:10.1103/PhysRevLett.124.212502

PMID:32530645

Abstract

The structure of a neutron-rich ^{25}F nucleus is investigated by a quasifree (p,2p) knockout reaction at 270A MeV in inverse kinematics. The sum of spectroscopic factors of π0d_{5/2} orbital is found to be 1.0±0.3. However, the spectroscopic factor with residual ^{24}O nucleus being in the ground state is found to be only 0.36±0.13, while those in the excited state is 0.65±0.25. The result shows that the ^{24}O core of ^{25}F nucleus significantly differs from a free ^{24}O nucleus, and the core consists of ∼35% ^{24}O_{g.s.}. and ∼65% excited ^{24}O. The result may infer that the addition of the 0d_{5/2} proton considerably changes neutron structure in ^{25}F from that in ^{24}O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

摘要

通过逆运动学中270A MeV的准自由（p，2p）敲出反应研究了丰中子(^{25}F)核的结构。发现(\pi0d_{5/2})轨道的光谱因子之和为1.0±0.3。然而，发现剩余(^{24}O)核处于基态时的光谱因子仅为0.36±0.13，而处于激发态时的光谱因子为0.65±0.25。结果表明，(^{25}F)核的(^{24}O)核心与自由(^{24}O)核有显著差异，该核心由约35%的(^{24}O_{g.s.})和约65%的激发态(^{24}O)组成。该结果可能推断，(0d_{5/2})质子的添加使(^{25}F)中的中子结构与(^{24}O)中的中子结构有很大变化，这可能是导致氧滴线异常的一种可能机制。