Structure of $X_b$ from line shape analysis

TL;DR

This paper investigates how the line shape of $B^ ext{*}ar{B}$ near threshold reveals the internal structure of the resonance $X_b$, emphasizing the importance of binding energy and elementary state probability.

Contribution

It demonstrates that the line shape analysis can determine the structure of $X_b$ by linking it to binding energy and elementary state probability.

Findings

Line shape depends on binding energy and elementary state probability.

Measurement of line shape can reveal the structure of $X_b$.

Sensitivity of line shape to parameters aids in understanding resonance composition.

Abstract

We study the production line shape of $B^\ast\bar B$ near threshold, where the $B^\ast \bar B$ pair comes from the resonance $X_b$. Our study shows that the line shape depends sensitively on the binding energy and the probability of finding an elementary state in the physical bound state. Both of the two parameters are crucial to identify the structure of $X_b$. Therefore, the line shape measurement can shed light on the structure of $X_b$.