HYP2018: 13th International Conference on Hypernuclear and Strange Particle Physics

On high-density $\Lambda^{\star}$ matter

Not scheduled

15m

2nd Floor

Abstract Submission

Speaker

Mr Schafer Martin (Nuclear Physics Institute Rez, Academy of Sciences of Czech Republic, 25069 Rez; Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 7, 11519 Prague 1, Czech Republic)

Description

The possible existence and stability of $\Lambda^{\star}$ (1405) matter was discussed recently by Akaishi and Yamazaki [1] who conjectured that it is stable against decay by both strong and weak interactions, thereby providing the absolute ground state of hadronic matter. In our own work, in preparation, we used a $\Lambda^{\star}\Lambda^{\star}$ interaction with short range attraction and a shorter range repulsion, fitting it to reproduce a binding energy value of $B_{\Lambda^{\star}\Lambda^{\star}}=40~$MeV taken from these authors' recent Faddeev-Yakubovsky calculation of a $K^- K^- p p$ bound state [2]. This $\Lambda^{\star}\Lambda^{\star}$ interaction was applied in Stochastic Variational Method (SVM) calculations of few-body $\Lambda^{\star}$ systems and also consistently within Relativistic Mean-Field (RMF) calculations of many-$\Lambda^{\star}$ systems. $\Lambda^{\star}$ absorption modes were also considered. We found that the binding energy per $\Lambda^{\star}$ in many-$\Lambda^{\star}$ systems saturates with the increasing number of $\Lambda^{\star}$ constituents, leaving $\Lambda^{\star}$(1405) matter comfortably above the corresponding aggregate of free $\Lambda$(1116) hyperons and decaying, thus, by the strong interactions to free hyperons. It is concluded, based on these calculations, that the existence of stable, condensed, and highly compressed $\Lambda^{\star}$ matter argued for in Ref. [1] is unlikely. [1] Y. Akaishi, T. Yamazaki, Phys. Lett. B 774 (2017) 522. [2] S. Maeda, Y. Akaishi, T. Yamazaki, Proc. Jpn. Acad. Ser. B 89 (2013) 418.