Bottomonium dipion transitions

TL;DR

This paper investigates bottomonium dipion transitions using a chiral decay model, considering various intermediate states and realistic wave functions, achieving spectra predictions that align well with experimental data.

Contribution

It introduces a detailed theoretical analysis of bottomonium dipion transitions incorporating intermediate B meson states and realistic wave functions, with spectra consistent with experiments.

Findings

Dipion spectra agree with experimental data

Inclusion of B meson intermediate states improves model accuracy

Adler zero condition constrains transition amplitudes

Abstract

Dipion transitions of the subthreshold bottomonium levels $\Upsilon (nS)\to \Upsilon (n'S) \pi\pi$ with $n>n', n=2,3,4, n'=1,2$ are studied in the framework of the chiral decay Lagrangian, derived earlier. The channels $B\bar B, B\bar B^*+ c.c, B^* \bar B^*$ are considered in the intermediate state and realistic wave functions of $\Upsilon (n S),B$ and $B^*$ are used in the overlap matrix elements. Imposing the Adler zero requirement on the transition matrix element, one obtains 2d and 1d dipion spectra in reasonable agreement with experiment.