Study of Possible Proton-Antiproton Hexaquark State in Lattice QCD

Abstract

We have used standard techniques of lattice quantum chromodynamics to look for evidence of the spin-zero six quark flavour singlet state ($J^{PC}=0^{-+}$) observed by BES Collaboration, and to determine the splitting between the mass of the possible proton-antiproton and the mass of two protons, its threshold. Using the various interpolating fields we find indications that for sufficiently light quarks proton-antiproton is slightly above the $2m_p$ threshold. The lattice resonance signal of binding observed near the physical and continuum regimes do not support the existence of proton-antiproton state as a spin-zero hexaquark state.

Comments: 4 pages, 5 figures, typos corrected, submitted for publication