Modification by pion exchange of near threshold resonance line shape in open heavy flavor channel

TL;DR

This paper investigates how pion exchange influences the line shape of near-threshold bottomoniumlike resonances decaying into B meson pairs, highlighting its importance in accurately determining resonance parameters.

Contribution

It introduces the effect of pion exchange on the line shape of near-threshold bottomoniumlike resonances, emphasizing its parametric enhancement due to heavy meson mass.

Findings

Pion exchange significantly affects resonance line shapes.

The effect is parametrically enhanced by the heavy meson mass.

Implications for precise determination of resonance parameters.

Abstract

The effect of the pion exchange on the line shape of near threshold bottomoniumlike resonances decaying into an $S$ wave pair of $B^{(*)}$ mesons is considered. It is pointed out that this effect, parametrically enhanced by the heavy meson mass, can be of a practical significance in determining the parameters of the bottomoniumlike resonances such as the known $Z_b(10610)$ and $Z_b(10650)$ states.