Hadron interaction with heavy quarkonia

TL;DR

This paper develops a parameter-free theoretical framework for hadro-quarkonium interactions, explaining observed resonance peaks and predicting new ones near open-flavor meson thresholds, without relying on molecular or tetraquark models.

Contribution

It introduces a novel, parameter-free approach to describe hadro-quarkonium systems through channel coupling and overlap integrals, providing explicit equations and numerical results.

Findings

Agreement with Belle's Z_b(10610) and Z_b(10650) peaks

Predicted resonance peaks at BB* and B*B* thresholds

Resonance origins linked to multichannel poles near thresholds

Abstract

Dynamics of hadro-quarkonium system is formulated, based on the channel coupling of a light hadron (h) and heavy quarkonium (Q\bar{Q}) to intermediate open-flavor heavy-light mesons (Q\bar{q}, \bar{Q}q). The resulting effective interaction is defined by overlap integrals of meson wavefunctions and (hq\bar q) coupling, where h is pi, rho, omega, phi, without fitting parameters. Equations for hadro-quarkonium amplitudes and resonance positions are written explicitly, and numerically calculated for the special case of pi Upsilon(nS) (n=1,2,3). It is also shown, that the recently observed by Belle two peaks Z_b(10610) and Z_b(10650) are in agreement with the proposed theory. It is demonstrated, that theory predicts peaks at the BB*, B*B* thresholds in all available pi Upsilon(nS) channels. Analytic nature of these peaks is investigated, and shown to be due to a common multichannel resonance poles close to the BB*, B*B* thresholds. The general mechanism of these hadro-quarkonium resonances does not assume any molecular or four-quark (tetraquark) dynamics.