The Pentaquark Candidates in the Dynamical Diquark Picture

TL;DR

This paper models pentaquark candidates as dynamically separated diquark-triquark systems, explaining their narrow widths and predicting isospin partners, advancing understanding of exotic hadron structures.

Contribution

It introduces a dynamical diquark-triquark model for pentaquarks, explaining their properties and predicting neutral partners, which is a novel approach compared to previous static models.

Findings

Explains narrow widths of $P_c^+$ states despite high mass.

Predicts isospin doublets with neutral partners.

Provides a dynamical mechanism for pentaquark formation.

Abstract

Starting with the dynamical picture of the exotic $c\bar c$-containing states $XY \! Z$ as the confinement-induced hadronization of a rapidly separating pair of a compact diquark and antidiquark, we describe the pentaquark candidates $P_c^+(4380)$ and $P_c^+(4450)$ in terms of a confined but rapidly separating color-antitriplet diquark $cu$ and color-triplet "triquark" $\bar c (ud)$. This separation explains the relatively small $P_c^+$ widths, despite these 5-quark systems lying far above both the $J/\psi \, p$ and $\Lambda_c \bar D^{(*)0}$ thresholds. The $P_c^+$ states are predicted to form isospin doublets with neutral partners $P_c^0$.