Known and exotic light hypernuclei studied with the 6Li+12C reaction at 2 A GeV

NUBA Conference Series -1: Nuclear Physics and Astrophysics

物理学;天文学

Saito, Take R^1,2,3,4 ; Bozkurt, Vakkas^1,5 ; Rappold, Christophe^1,6

GSI Helmholtz Centre for Heavy Ion Research, Planckstrasse 1, Darmstadt

64291, Germany^1

Johannes Gutenberg-Universität Mainz, J.J.Becherweg 40, Mainz

55099, Germany^2

Helmholtz Institute Mainz (HIM), J.J.Becherweg 40, Mainz

55099, Germany^3

Iwate University, Morioka, Iwate

020-8550, Japan^4

Nigde University, Nigde

51100, Turkey^5

Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, Giessen

35392, Germany^6

关键词: Bound state;    Decay vertex;    Final state;    Invariant mass;    Lifetime data;    Lifetime values;    Natural carbons;    Theoretical modeling;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/590/1/012018/pdf
DOI  :  10.1088/1742-6596/590/1/012018

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

Light hypernuclei have been studied by using induced reactions of6Li projectiles bombarded on the natural carbon target by means of the invariant mass method, and3ΛH and4ΛH hypernuclei as well as Λ-hyperons are produced and identified. Significance values of3ΛH,4ΛH and Λ are respectively 4.7σ, 4.9σ and 6.7σ. By analyzing decay vertices of3ΛH,4ΛH and Λ by means of unbinned maximum likelihood fitting their lifetime values have been deduced to be 183+42-32 ps, 140+48-33 ps and 262+56-43 ps, respectively. In addition, signals appeared for the d+π-and t+π-final states in the analyses on invariant mass and lifetime. Those signals have suggested a possible bound state of two neutrons with Λ,3Λn. It has also been revealed for the first time that the lifetime of3ΛH is significantly shorter than that of Λ, which is consistent to the statistical analyses including all the lifetime data reported in the past. However, there is no theoretical model to explain the short lifetime of3ΛH as well as the existence of the3Λn bound state. These should be further experimentally and theoretically studied.