Event Information
Title:

"Search for neutron-rich hypernuclei: Lambda-6H and beyond"

Type:

Joint Seminar

Sponsor:

Department of Particle Physics and Astrophysics
Nuclear Physics Joint Seminar

Lecturer:

Avraham Gal
The Hebrew University

Date:

Monday, April 8, 2013

Time:

16:15 - 17:15

Location:

Hebrew University, Jerusalem

15:45 - 16:15 Coffee Break
In this talk I review recent experimental evidence presented by the FINUDA Collaboration in the e e --> Phi --> K K- DAFNE machine at Frascati, Italy, for a particle stable Lambda-6H, with one proton and four neutrons stabilized by a Lambda hyperon [1]. Ongoing few-body calculations of Lambda-6H as well as shell-model estimates for its stability will also be briefly reviewed. The Lambda-6H hypernucleus was highlighted by Akaishi [2] as a test ground for the significance of Lambda N <-> Sigma N coupling in Lambda hypernuclei, spurred by the role it plays in s-shell hypernuclei and by the far-reaching consequences it might have for dense neutron-star matter with strangeness. The discovery of Lambda-6H has stirred renewed interest in charting domains of particle-stable neutron-rich Lambda hypernuclei, particularly for unbound nuclear cores.

Millener and I have studied within a shell-model approach several neutron rich Lambda hypernuclei in the nuclear p shell that could be formed in (pi-,K ) (ongoing experiment E10 at J-PARC, Japan) or in (K-,pi ) reactions on stable nuclear targets. The hypernuclear shell-model input was taken from a theoretically inspired successful fit of gamma-ray transitions in p-shell Lambda hypernuclei. Predictions for binding energies of Lambda-9He, Lambda-10Li, Lambda-12Be and Lambda-14B will be reviewed, concluding that none of the large effects conjectured by Akaishi to arise from Lambda N <-> Sigma N coupling is borne out by our realistic shell-model calculations.