Model-independent mass determination of near-threshold states from short-range production

Abstract

We propose a novel observable for the precision measurements of a wide class of near-threshold dimer states: the short-range production rate of a dimer--spectator two-body system, composed of the given near-threshold state and one of its constituents. Within the framework of nonrelativistic effective field theory, these production rates exhibit characteristic line shapes for the specific partial wave and reach a model-independent minimum. This feature enables a precise extraction of their masses from experimental data, provided that the line shape can be resolved with sufficient accuracy. Applying this novel method to both the $T_{b\bar{b}1}(10610)B$ and $T_{b\bar{b}1}(10650)B^*$ systems allows for a precise determination of the binding energy $δ$ of the $T_{b\bar{b}1}(10610)$ and $T_{b\bar{b}1}(10650)$ via the relation of $δ=-{E_{\text{dip}}^{\text{exp}}}/{0.1983}$ once the respective dip position $E_{\text{dip}}^{\text{exp}}$ is experimentally identified.