Structure of 20ΛNe Hypernucleus

Abstract

A ('He+ 16 0+A) and (a+ 15 0+A) channel coupling cluster model of ,:\,Ne is presented. The energy spectra, RMS radii and spectroscopic factors are calculated. The ground state with unusual negative parity is predicted and is shown to be the result of the different responses of shell structure and cluster structure to the glue· like role of A particle. How to test the predicted negative parity ground state experimentally is discussed. § 1. Introduction

Deformation of hypernuclei studied with antisymmetrized molecular dynamics

“…On the contrary, the in a p wave coupled to the deformed core has greater binding than does one coupled to a spherical core. This contradicts the findings of a preceding study [7], in which the parity inversion of 20 Ne was predicted.…”

“…Based on the cluster model calculation, the parity inversion in 20 Ne was suggested by Sakuda and Bandō [7]. The core nucleus 19 Ne has the α + 15 O cluster state (J π = 1/2 − 1 ) 238 keV above the ground state (J π = 1/2 + ), which has the (sd) 3 shell structure [41].…”

“…Many theoretical works have suggested that such phenomena, caused by a particle, result in changes of deformation [1][2][3][4][5], shrinkage of the intercluster distance [1,2], and creation of the supersymmetric (genuine) hypernuclear state [2,[6][7][8][9]. Owing to experimental developments, some of these phenomena have been observed in light p-shell hypernuclei.…”

“…Owing to experimental developments, some of these phenomena have been observed in light p-shell hypernuclei. As examples, we can refer to the reduction of B(E2) in 7 Li [10] and the identification of the supersymmetric (genuine) hypernuclear state in 9 Be [11][12][13].…”

“…Since the normal forms of these nuclei have a variety of structures, such as a coexistence of shell and cluster structure [14][15][16] and novel exotic clustering [17][18][19][20][21], there must be many interesting phenomena peculiar to hypernuclei to be found. Indeed, several pioneering works have predicted exotic structures in sd-shell hypernuclei, such as parity inversion in 20 Ne [7] and various rotational bands in 21 Ne [22]. These works have been based on rather limited knowledge of the N interaction.…”