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 $T_{b\bar{b}1}(10650)B^{\ast }$ systems allows for a precise determination of the binding energy $\delta$ of the $T_{b\bar{b}1}(10610)$ and $T_{b\bar{b}1}(10650)$ via the relation of $\delta =-E_{\text{dip}}^{\text{exp}}/0.1983$ once the respective dip position $E_{\text{dip}}^{\text{exp}}$ is experimentally identified.

Comments: 8 pages, 6 figures; updated to the accepted version