Holographic QCD for H-dibaryon (uuddss)

Hideo Suganuma,Kohei Matsumoto,Y Foka,N Brambilla,V Kovalenko

doi:10.1051/epjconf/201713713018

Abstract

The H-dibaryon (uuddss) is studied in holographic QCD for the first time. In holographic QCD, four-dimensional QCD, i.e., SU($N_c$) gauge theory with chiral quarks, can be formulated with $S^1$-compactified D4/D8/$\overline{\rm D8}$-brane system. In holographic QCD with large $N_c$, all the baryons appear as topological chiral solitons of Nambu-Goldstone bosons and (axial) vector mesons, and the H-dibaryon can be described as an SO(3)-type topological soliton with $B=2$. We derive the low-energy effective theory to describe the H-dibaryon in holographic QCD. The H-dibaryon mass is found to be twice of the $B=1$ hedgehog-baryon mass, $M_{\rm H} \simeq 2.00 M_{B=1}^{\rm HH}$, and is estimated about 1.7GeV, which is smaller than mass of two nucleons (flavor-octet baryons), in the chiral limit.

Highlights

Nowadays, QCD is established as the fundamental theory of the strong interaction, and all the experimentally observable hadrons have been considered as color-singlet composite particles of quarks and gluons
We study the H-dibaryon and its properties in the chiral limit using holographic QCD [13], which has a direct connection to QCD, unlike most effective models
Since the nucleon mass MN is larger than the B = 1 hedgehog mass MBH=H1 by the rotational energy [6, 8], the H-dibaryon mass is smaller than mass of two nucleons, MH < 2MN, in the chiral limit

Summary

Introduction

QCD is established as the fundamental theory of the strong interaction, and all the experimentally observable hadrons have been considered as color-singlet composite particles of quarks and gluons. In 1985, the H-dibaryon was investigated [4, 5] in the Skyrme-Witten model [6,7,8] These two model calculations suggested a low-lying Hdibaryon below the ΛΛ threshold, which means the stability of H against the strong decay. It is still interesting to consider the stability of H-dibaryons in the SU(3) flavorsymmetric case of mu = md = ms [10,11,12], because the large mass of H may be due to an SU(3) flavor-symmetry breaking by the large s-quark mass, ms ≫ mu,d, in the real world. We investigate the H-dibaryon mass from the viewpoint of its stability in the chiral limit

Holographic QCD

QCD-equivalent D-brane system

Low-energy effective theory

H-dibaryon Solution in Holographic QCD

30 With Vector Meson

Summary and Concluding Remarks