Prediction of charmed-bottom pentaquarks in quark model

TL;DR

This paper predicts the existence of several fully heavy charm-bottom pentaquark states using the chiral quark model, suggesting they are likely molecular states with small binding energies, guiding future experimental searches.

Contribution

It provides the first systematic theoretical prediction of fully heavy charm-bottom pentaquark candidates, including their quantum numbers and properties, within the chiral quark model.

Findings

Several pentaquark candidates with specific quark compositions and quantum numbers identified.

Predicted states have binding energies below 10 MeV and RMS around 1.8 fm.

States are likely molecular, offering new directions for experimental detection.

Abstract

Inspired by the fully heavy tetraquark states reported by the LHCb, ATLAS and CMS Collaborations, we perform a systemical investigation of the low-lying fully heavy pentaquark systems composed of charm and bottom quarks (anti-quark) in the chiral quark model. With the help of the channel-coupling, we obtain several fully heavy pentaquark candidates, which are $cccc\bar{b}$ and $bbbb\bar{c}$ systems with $J^P = 1/2^-$ and $3/2^-$, $cccb\bar{c}$, $bbbc\bar{b}$, $cccb\bar{b}$ and $bbbc\bar{c}$ systems with $J^P = 5/2^-$. The binding energies of these states are all below 10 MeV and the root mean square (RMS) are around 1.8 fm, which indicates that these states are likely to be molecular states. These predicted exotic states may provide new ideas for experimental searches and we expect more experimental and theoretical researches to study and understand the fully heavy states in future.