Single eta production in heavy quarkonia transitions

TL;DR

This paper investigates eta meson production in bottomonium transitions using a parameter-free method, finding results consistent with recent experimental data, especially for the transition from n=4 to n'=1.

Contribution

It applies a previously used method to eta production in heavy quarkonia transitions, providing parameter-free calculations for multiple transitions.

Findings

Calculated widths match recent experimental data.

The width for the 4→1 transition is notably large.

Method successfully predicts eta production without fitting parameters.

Abstract

The $\eta$ production in the $(n,n')$ bottomonium transitions $\Upsilon (n) \to \Upsilon (n') \eta, $ is studied in the method used before for dipion heavy quarkonia transitions. The widths $\Gamma_\eta(n,n')$ are calculated without fitting parameters for $n=2,3,4,5, n'=1$.Resulting $\Gamma_\eta(4,1)$ is found to be large in agreement with recent data.