The singly charmed pentaquark molecular states via the QCD sum rules

Abstract

In this work, we systematically investigate the singly charmed pentaquark molecular states [Formula: see text], [Formula: see text] and [Formula: see text] with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 13 and taking fully account of the light-flavor [Formula: see text] breaking effects. The numerical results favor assigning the [Formula: see text] as the [Formula: see text] molecular state with the [Formula: see text] and [Formula: see text], assigning the [Formula: see text] as the [Formula: see text] molecular state with the [Formula: see text] and [Formula: see text], assigning the [Formula: see text] as the [Formula: see text] molecular state with the [Formula: see text] and [Formula: see text], and assigning the [Formula: see text] as the [Formula: see text] molecular state with the [Formula: see text] and [Formula: see text]. Other potential molecule candidates are also predicted, which may be observed in future experiments. For example, we can search for the [Formula: see text] and [Formula: see text] molecular states with the isospin [Formula: see text] in the [Formula: see text] and [Formula: see text] mass spectrum, respectively, in the future, which could shed light on the nature of the [Formula: see text].