Baryon interactions from lattice QCD with physical masses — strangeness S = -1 sector —

Hidekatsu Nemura,Sinya Aoki,Tetsuo Hatsuda,Takumi Iritani,Takaya Miyamoto,Yoichi Ikeda,Kenji Sasaki,Takashi Inoue,Takumi Doi,Shinya Gongyo,Noriyoshi Ishii

doi:10.1051/epjconf/201817505030

Abstract

We present our recent results of baryon interactions with strangeness S = −1 based on Nambu-Bethe-Salpeter (NBS) correlation functions calculated fromlattice QCD with almost physical quark masses corresponding to (mk,mk) ≈ (146, 525) MeV and large volume (La)4 ≈ (96a)4 ≈ (8.1 fm)4. In order to perform a comprehensive study of baryon interactions, a large number of NBS correlation functions from NN to ΞΞ are calculated simultaneously by using large scale computer resources. In this contribution, we focus on the strangeness S = −1 channels of the hyperon interactions by means of HAL QCD method. Four sets of three potentials (the 3S1 − 3 D1 central, 3S1 − 3 D1 tensor, and the 1S0 central potentials) are presented for the ∑N − ∑N (the isospin I = 3/2) diagonal, the ∧N − ∧N diagonal, the ∧N → ∑N transition, and the ∑N − ∑N (I = 1/2) diagonal interactions. Scattering phase shifts for ∑N (I = 3/2) system are presented.

Highlights

Nuclear force and strangeness nuclear forces provide an important starting point to understand how hypernuclei are bound, in which hyperons are embedded in normal nuclei as “impurities”[1]
A normal nucleus is successfully described by utilising the high precision nucleon-nucleon (NN) potentials together with a three-nucleon force a quantitatively same-level description of a hypernucleus is still difficult because of large uncertainties of hyperon-nucleon (Y N) and hyperon-hyperon (YY) interactions; those Y N and YY potentials are not well constrained from experimental data due to the short life time of hyperons
For the ΣN (I = 3/2) interaction, phase shifts are calculated for the 3S 1 −3 D1 and 1S 0 states

Summary

Introduction

Nuclear force and strangeness nuclear forces provide an important starting point to understand how hypernuclei are bound, in which hyperons (or strange quarks) are embedded in normal nuclei as “impurities”[1] Determining how such a baryon-baryon interaction is described from a fundamental perspective is a challenging problem in physics. Such quantitative understanding is useful to study properties of hyperonic matters inside the neutron stars, where recent observations of massive neutron star heavier than 2M⊙ [3, 4] may be issued against a hyperonic equation of state (EOS) employed in such a study. Better understanding of Y N and YY is becoming increasingly important due to the observation of the binary neutron star merger[5, 6]

Objectives

Results

Conclusion