Investigation of full heavy $ QQQQ'\bar{Q}$ pentaquark candidates

TL;DR

This study predicts masses and analyzes properties of potential heavy-quark pentaquark states with specific quark compositions, contributing to the understanding of exotic hadrons in particle physics.

Contribution

It provides the first detailed spectroscopic analysis and mass predictions for heavy $cccb\bar{c}$ and $bbbc\bar{b}$ pentaquark candidates, including their current couplings.

Findings

Mass of $P_{(4cb)}$ around 11388 MeV with ~108 MeV uncertainty.

Mass of $P_{(4bc)}$ around 21000 MeV with ~122 MeV uncertainty.

Calculated current coupling constants for decay analysis.

Abstract

Recent breakthroughs in research and experimentation have led to the identification of numerous exotic states in particle physics. Each new discovery not only sparks excitement for future findings but also fuels interest in uncovering additional unknown states. Motivated by this perspective and the recent identification of both standard and exotic hadrons with an increasing number of heavy quarks, this study conducts a spectroscopic analysis of possible pentaquark candidates with spin-parity $\frac{1}{2}^-$, and quark content of $cccb\bar{c}$ and $bbbc\bar{b}$. The masses of these states are calculated by considering the relevant Lorentz structures, including $\slashed{p}$ and $\mathbbm{1}$, yielding the following results, respectively: for the $P_{(4cb)}$ state, $m_{P_{(4cb)}} = 11388.30 \pm 107.79$~MeV and $m_{P_{(4cb)}} = 11368.30 \pm 112.68$~MeV, and for the $P_{(4bc)}$ state, $m_{P_{(4bc)}} = 20998.30 \pm 121.52$~MeV and $m_{P_{(4bc)}} = 20990.50 \pm 125.87$~MeV. Additionally, the current coupling constants of these states to the vacuum, which are essential for analyzing their potential decay modes, are also provided in this study.