The Spectra of $p\bar{\Lambda }$ and $p\bar{\Sigma }$ Hexaquark States

Abstract

Motivated by the observation of the $J^P=1^{+}$ resonance $X(2085)$ in the $p\bar{\Lambda }$ system by the BESIII collaboration, we studied the molecular states of hexaquarks $p\bar{\Lambda }$ and $p\bar{\Sigma }$ with baryon-antibaryon structures within the framework of the QCD sum rules. Non-perturbative contributions up to dimension 13 were considered in our analysis. The results indicate the existence of six possible molecular states $p\bar{\Lambda }$ and $p\bar{\Sigma }$, with quantum numbers $J^P=0^{-},0^{+},1^{-}$. Consequently, the current sum rule results do not support the interpretation of $X(2085)$ as a $p\bar{\Lambda }$ or $p\bar{\Sigma }$ molecular state. On the other hand, we find that the masses of the proposed $p\bar{\Lambda }$ and $p\bar{\Sigma }$ structures with $J^P=1^{-}$ are in the vicinity of observed $X(2075)$, which implies that the nature of this state needs more invistigations. Moreover, the possible decay modes of the concerned hexaquark states are analyzed.

Comments: 32 pages, 7 figures