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

Fully coupled-channel study of $K^-pp$ resonance in a chiral SU(3)-based $\bar{K}N$ potential

Not scheduled

15m

2nd Floor

Abstract Submission

Speaker

Dr Akinobu Dote (KEK theory center/IPNS, High Energy Accelerator Research Organization)

Description

“$K^-pp$” is the most essential system of kaonic nuclei which are expected to have several exotic nature, such as formation of dense state, due to the strong $\bar{K}N$ attraction [1]. Many researchers have eagerly investigated this system from both theoretical and experimental sides for a long time, expecting that the $K^-pp$ might give some hints to reveal detailed nature of kaonic nuclei. In theoretical sides, indeed, since the $K^-pp$ is just a three-body system, it has been investigated with various methods. As a result, we have reached a consensus that the $K^-pp$ should exist between $\bar{K}NN$ and $\pi\Sigma N$ thresholds as a resonant state, but that its binding energy still depends on the $\bar{K}N$ potential employed in models [2]. In the experimental side, J-PARC E15 group has conducted a $K^-pp$ quasi-bound state search experiment. They are going to report the result of their second-run experiment with high statics [3], and the $\Lambda p$ invariant-mass spectrum shows a clear signal between $\bar{K}NN$ and $\pi\Sigma N$ thresholds. Under such a current situation, we have developed a novel method, ***“Fully coupled-channel complex scaling method (Full ccCSM)”***, to deal with the $K^-pp$ system as accurately as possible [4]. In the theoretical viewpoint, the $K^-pp$ is considered to be a coupled-channel system of $\bar{K}NN$, $\pi\Sigma N$ and $\pi\Lambda N$. In addition, as described above it should be a resonant state. We consider that coupled-channel aspect and resonance aspect are important in the theoretical study of $K^-pp$. The full ccCSM can handle both aspects correctly, and additionally it provides us with a wave function to analyze the nature of the $K^-pp$ system. Therefore, we expect that the full ccCSM is the most suitable method to investigate the $K^-pp$. With the full ccCSM, we have investigated the $K^-pp$ system, using a $\bar{K}N$ potential which is based on the chiral-SU(3) theory [5], since anti-kaon and pion are Nambu-Goldstone bosons and they are governed by the chiral dynamics. We will report the result of our self-consistent calculation in which we take into account the energy dependence involved in such a chiral SU(3)-based $\bar{K}N$ potential. If possible, we will show the result obtained in a semi-relativistic framework which should be better for light mesons. References: [1] Y. Akaishi and T. Yamazaki, Phys. Rev. C 65, 044005 (2002). [2] A. Gal, E. V. Hungerford and D. J. Millener, Rev. Mod. Phys. 88, 035004 (2016). [3] F. Sakuma (J-PARC E15 collaboration), JPS Conf. Proc.13, 010002 (2017). [4] A. Dote, T. Inoue and T. Myo, Phys. Rev. C 95, 062201(R) (2017). [5] A. Dote, T. Inoue and T. Myo, arXiv:1710.07589.

Summary

I will talk on our study of the most essential kaonic nucleus "$K^-pp$" with "Fully coupled-channel complex scaling method (Full ccCSM)" which resects key ingredients of coupled channel and resonance for the $K^-pp$ study. In our recent calculation, we have employed a chiral SU(3)-based $\bar{K}N$ potential and conducted a self-consistent calculation taking into account the energy dependence involved there. In my talk, I will report the latest result of our study of the $K^-pp$ with full ccCSM.