Masses of the conjectured H-dibaryon at different temperatures

Abstract

Abstract We present a lattice QCD determination of masses of the conjectured H-dibaryon $m_H$ at nine different temperatures
 $T/T_c =0.24, 0.63, 0.76, 0.84, 0.95, 1.09, 1.27, 1.52, 1.90$. In the meantime, the masses of baryon $N$, $\Sigma$, $\Xi$ and $\Lambda$ at different temperatures
 are also computed.
 The simulation is performed on anisotropic lattice with $N_f=2+1$ flavours of clover fermion at quark mass
 which corresponds to $m_\pi=384(4) {\rm MeV} $. The thermal ensembles were provided by the FASTSUM
 collaboration and the zero temperature ensembles by the Hadspec collaboration. We also calculate the spectral density of the correlation function of those particles.
 The spectral density distributions show rich peak structure at the lowest temperature, while at intermediate temperatures, the mass values of those particles obtained by extrapolation method reflect a two-peak structure.
 While the spectral density for octet baryon becomes smooth at $T/T_c = 1.27, 1.52, 1.90$, the spectral density for H-dibaryon becoms smooth at $T/T_c = 1.90$.
 At $T/T_c =0.24 $, the mass difference of H-dibaryon
 and
 $\Lambda$ pair $\Delta m = m_H - 2\,m_{\Lambda} $ is estimated to be $\Delta m = -14.6(6.2) {\rm MeV}$ which suggests there exists a bound H-dibaryon state. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.