Dipion transitions of the subthreshold bottomonium levels Υ(nS)→Υ(n′S)ππ with n>n′,n=2,3,4,n′=1,2 are studied in the framework of the chiral decay Lagrangian, derived earlier. The channels BBˉ,BBˉ∗+c.c,B∗Bˉ∗ are considered in the intermediate state and realistic wave functions of Υ(nS),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.
@article{arxiv.0804.4635,
title = {Bottomonium dipion transitions},
author = {Yu. A. Simonov and A. I. Veselov},
journal= {arXiv preprint arXiv:0804.4635},
year = {2009}
}