\Upsilon(5S) decays into BB and BB\pi

Abstract

Two- and three-body decays of ${\rm Y}(5S)$ into $BB,$$B{B}^{\ast },$ $B^{\ast }{B}^{\ast },$ $B_s{B}_s,$ $B_s{B}_s^{\ast },$ $B_s^{\ast }{B}_s^{\ast }$ and $B{B}^{\ast }\pi ,B^{\ast }{B}^{\ast }\pi$ are evaluated using the theory, developed earlier for dipion bottomonium transitions. The theory contains only two parameters, vertex masses $M_{br}$ and $M_{\omega }$, known from dipion spectra and width. Predicted values of ${\Gamma }_{tot}(5S)$ and six partial widths ${\Gamma }_k(5S),k=BB,B{B}^{\ast },...$ are in agreement with experiment. The decay widths ${\Gamma }_{5S}(\pi B{B}^{\ast })$ and ${\Gamma }_{5S}(\pi B^{\ast }{B}^{\ast })$ are also calculated and found to be of the order of 10 keV.

Comments: 6 pages