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, $ΛΛ$, $N Ξ$ and $ΣΣ$. 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_π=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 $ΣΣ$ 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 $Δm = m_H - 2\,m_Λ $ of H-dibaryon and $Λ$ pair at $T/T_c =0.24 $ for five channels are also estimated. The results show that $Δm = m_H - 2\,m_Λ $ for channels of 27-plet and $ΛΛ$ is positive, while $Δm = m_H - 2\,m_Λ $ for channels of singlet, $N Ξ$ and $ΣΣ$ is negative.

Figures (5)

• Figure 1: Euclidean correlators $G(\tau)/G(0)$ of $H_1$, $H_{27}$, $H_{\Lambda\Lambda}$, $H_{N\Xi}$ and $H_{\Sigma\Sigma}$ as a function of $\tau T$ at $N_t = 128$ lattice corresponding to the lowest temperature $T/T_c =0.24$. The correlators at some points are not displayed due to the minus value. The vertical axis is rescaled logarithmically
• Figure 2: Euclidean correlator $G(\tau)/G(0)$ of $H_1$, $H_{27}$, $H_{\Lambda\Lambda}$, $H_{N\Xi}$ and $H_{\Sigma\Sigma}$ as a function of $\tau T$ at $N_t = 48$ lattice corresponding to the temperature $T/T_c =0.63$. The vertical axis is rescaled logarithmically
• Figure 3: Linear extrapolation of mass values for $H_1$ on $N_\tau=128$ ensembles. The data points indicated by solid squares are excluded in the extrapolation procedure, while the data points represented by solid circles are included. Horizontal axis represents inverse values of time slices suppressed.
• Figure 4: Mass values for $H_1$, $H_{27}$, $H_{\Lambda\Lambda}$, $H_{N\Xi}$ and $H_{\Sigma\Sigma}$ at different temperatures.
• Figure 5: Spectral density of $H_1$, $H_{27}$, $H_{\Lambda\Lambda}$, $H_{N\Xi}$ and $H_{\Sigma\Sigma}$ at different temperatures.