Exotic Heavy Hadrons

TL;DR

This paper reviews recent advances in understanding exotic heavy hadrons, focusing on color interactions in pentaquarks and the potential formation of stable multihadron molecules, including a specific $T_{bbb}$ state.

Contribution

It introduces a unified framework for explaining hidden heavy-flavor pentaquarks and explores the formation and properties of multihadron exotic states like $T_{bbb}$.

Findings

Color interaction models explain observed pentaquark patterns.

A bound state of three $B$ mesons ($T_{bbb}$) is predicted.

Resonance decay widths reveal internal structure insights.

Abstract

We review our recent findings on the structure and properties of exotic heavy hadrons, focusing on two main topics. First, we examine the role of correlations driven by the short-range Coulomb-like color interaction in hidden heavy-flavor pentaquarks. We show how this framework consistently accounts for the observed pattern of $P_c$ and $P_{cs}$ states in the hidden-charm sector and enables predictions for the hidden-bottom sector, where experimental data are still lacking. The second topic explores the possibility of forming stable multihadron molecules from deeply bound two-hadron exotic states. In this context, a bound state of three $B$ mesons, denoted as $T_{bbb}$, with quantum numbers $(I)J^P = (1/2)2^-$, is presented. We find that the binding energy generally decreases as the number of hadrons increases, primarily due to effects of the Pauli principle and the appearance of new decay thresholds. Nonetheless, resonances may still arise in specific cases, depending on the internal thresholds of the system. Finally, we discuss how the decay width of an exotic multihadron resonance can offer valuable insights into its internal structure and underlying~dynamics.