Production of $ B \bar{B}$ bound state via $\Upsilon (4S)$ radiative decays

TL;DR

This paper estimates the production rate of a hypothesized $ B ar{B}$ bound state, called $X(10550)$, via $Upsilon(4S)$ radiative decays using an effective Lagrangian approach, providing predictions for experimental searches.

Contribution

It introduces a novel calculation of the $X(10550)$ production rate in $Upsilon(4S)$ decays, employing triangle diagrams and the compositeness condition, which has not been done before.

Findings

Partial decay width estimated between 0.5 and 192 keV.

Branching fraction predicted between 10^{-5} and 10^{-3}.

Results suggest experimental detectability of $X(10550)$ in current and future experiments.

Abstract

Motivated by recent theoretical predictions about the existence of a $ B \bar{B}$ bound state (also denoted as $ X(10550) $), in this work we estimate the production of the $S$-wave $ B^+ B^-$ molecule via $\Upsilon (4S)$ radiative decays. In particular, we make use of effective Lagrangian approach and the compositeness condition to calculate the $ X(10550) $ production rate via $\Upsilon(4S)\rightarrow \gamma X(10550)$ decays employing triangle diagrams. Our results show that the partial decay width of this reaction is of the order of $0.5 - 192 \ \keV $ for a respective binding energy of $1 - 100 $ MeV, corresponding to a branching fraction of $ 10^{-5} - 10^{-3}$. These findings suggest that the existence of the $ X(10550) $ might be checked via the analysis of the mentioned decay in present and future experiments.