Branching fraction measurements of the rare $B_s^0\to \ddot{I}•\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ and $B_s^0\to f_2^{\prime }(1525)\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decays

Abstract

The branching fraction of the rare $B_s^0\to \ddot{I}•\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decay is measured using data collected by the LHCb experiment at center-of-mass energies of $7$, $8$ and $13\mathrm{TeV}$, corresponding to integrated luminosities of $1$, $2$ and $6{\mathrm{fb}}^{-1}$, respectively. The branching fraction is reported in intervals of $q^2$, the square of the dimuon invariant mass. In the $q^2$ region between $1.1$ and $6.0{\mathrm{Ge}\mathrm{V}}^2/c^4$, the measurement is found to lie $3.6$ standard deviations below a Standard Model prediction based on a combination of Light Cone Sum Rule and Lattice QCD calculations. In addition, the first observation of the rare $B_s^0\to f_2^{\prime }(1525)\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decay is reported with a statistical significance of nine standard deviations and its branching fraction is determined.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2021-014.html (LHCb public pages)