Exotic baryons from a heavy meson and a nucleon

TL;DR

This paper investigates the formation of exotic baryons as hadronic molecules composed of a heavy meson and a nucleon, highlighting the role of pion exchange and heavy quark symmetry in predicting bound and resonant states.

Contribution

It introduces a model respecting heavy quark symmetry to evaluate heavy meson-nucleon systems, revealing numerous bound and resonant states, especially in isospin I=0.

Findings

Strong attraction from pion exchange leads to bound states.

Many I=0 resonances and bound states are predicted.

Few resonances are found in I=1 states.

Abstract

We evaluate a hadronic molecule formed by a heavy meson and a nucleon respecting heavy quark symmetry. The tensor force of pion exchange potential plays a dominate role to produce an strong attraction in this system. Solving coupled channel Schr\"odinger equations for PN and P* N, we find many bound and resonant states with isospin I=0 while there are few resonances in I=1 state. The rich structures with I=0 indicate that the spectrum of heavy baryons near the threshold is influenced by the contributions from such hadron composite structures.