Speaker
Description
We present a preliminary lattice QCD study of the H-dibaryon at a close-to-physical pion mass through the spectroscopic analysis of the strangeness $S=-2$, iso-singlet baryon-baryon system on the CLS D200 ensemble. This ensemble is at $m_\pi \simeq 200~\mathrm{MeV}$ and $m_K \simeq 480~\mathrm{MeV}$, using a $64^3 \times 128$ lattice with spacing $a \simeq 0.065~\mathrm{fm}$ and open boundary conditions in the temporal direction.
In this study, we determined the finite-volume spectrum using a GEVP on the $\Lambda\Lambda$, $N\Xi$, and $\Sigma\Sigma$ channels. Based on these results, a preliminary multi-channel Lüscher analysis of the extracted energy levels was performed. Firstly, with simple parametrisations of the inverse $K$ matrix, with the aim of extending the analysis to more flexible models. Particular attention is paid to left-hand cuts arising from one-particle exchanges, entering at $t=m_{\pi}^2$ in the $N\Xi$ and $\Sigma\Sigma$ channels in the relevant energy region.