Heavy Quark Symmetry Predictions for Weakly Bound B-Meson Molecules

TL;DR

This paper develops an effective field theory based on heavy quark spin symmetry to predict properties of newly observed bottom meson molecules, including line shapes and decay rates.

Contribution

It introduces a novel effective field theory framework for B-meson molecules that incorporates heavy quark spin symmetry and predicts their observable properties.

Findings

Predicted line shapes near B(*)B(*) thresholds.

Calculated decay rates of bottom meson bound states.

Derived new heavy quark spin symmetry relations for parameters.

Abstract

Recently the Belle collaboration discovered two resonances, Zb(10610) and Zb(10650), that lie very close to the B\bar{B}^* and B^*\bar{B}^* thresholds, respectively. It is natural to suppose that these are molecular states of bottom and anti-bottom mesons. Under this assumption, we introduce an effective field theory for the Zb(10610) and Zb(10650), as well as similar unobserved states that are expected on the basis of heavy quark spin symmetry. The molecules are assumed to arise from short-range interactions that respect heavy quark spin symmetry. We use the theory to calculate line shapes in the vicinity of B^{(*)}\bar{B}^{(*)} thresholds as well as two-body decay rates of the new bottom meson bound states. We derive new heavy quark spin symmetry predictions for the parameters appearing in the line shapes as well as the total and partial widths of the states.