Masses of the conjectured H-dibaryon for different channels at different temperatures

Abstract

We present a lattice QCD spectroscopy study of the conjectured H dibaryon for 5 different channels at nine different temperatures. The H dibaryon operator is constructed with five different channels which are flavor singlet, flavor 27-plet, $\Lambda \Lambda$, $N \Xi$ and $\Sigma \Sigma$. The nine different temperatures range from $T/T_c =0.24$ to $T/T_c = 1.90$. The simulations are 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. The simulations show that the mass of H-dibaryon for 27-plet channel is the largest at different temperatures, while the mass for $\Sigma \Sigma $ channel is the lightest. We also calculate the spectral function of the correlation function of H dibaryon for five channels. The spectral density distributions exhibit similar behavior for the five channels. The mass differences $\Delta m = m_H - 2\,m_{\Lambda} $ of H-dibaryon and $\Lambda$ pair at $T/T_c =0.24 $ for five channels are also estimated. The results show that $\Delta m = m_H - 2\,m_{\Lambda} $ for channels of 27-plet and $\Lambda \Lambda$ is positive, while $\Delta m = m_H - 2\,m_{\Lambda} $ for channels of singlet, $N \Xi$ and $\Sigma \Sigma$ is negative.