Stable heavy pentaquarks in constituent models

TL;DR

This paper demonstrates that standard constituent quark models predict stable hidden-charm pentaquarks below dissociation thresholds, emphasizing their complex internal structure beyond simple molecular states.

Contribution

It shows that constituent quark models can produce stable hidden-charm pentaquarks with unique internal color configurations, not reducible to molecular states.

Findings

Predicted pentaquarks are stable against dissociation.

Binding arises from chromoelectric and chromomagnetic interactions.

Wave functions include color sextet and octet configurations.

Abstract

It is shown that standard constituent quark models produce $(\bar c c qqq)$ hidden-charm pentaquarks, where $c$ denotes the charmed quark and $q$ a light quark, which lie below the lowest threshold for spontaneous dissociation and thus are stable in the limit where the internal $\bar c c$ annihilation is neglected. The binding is a cooperative effect of the chromoelectric and chromomagnetic components of the interaction, and it disappears in the static limit with a pure chromoelectric potential. Their wave function contains color sextet and color octet configurations for the subsystems and can hardly be reduced to a molecular state made of two interacting hadrons. These pentaquark states could be searched for in the experiments having discovered or confirmed the hidden-charm meson and baryon resonances.