Measurement of the branching fractions of $B_s^{0} \rightarrow D_s^{(*)+} D_s^{(*)-}$ decays at CDF

The CDF collaboration reports on an improved measurement of $B_s^{0} \rightarrow D_s^{(*)+} D_s^{(*)-}$ branching fractions using 5.3 fb$^{-1}$ of data. The $D_s^{+}$ meson is reconstructed by selecting two narrow mass bands of phase space of the $KK\pi$ final state and accounting for the full $KK\pi$ Dalitz structure in the reconstruction efficiencies for the first time. Assuming the semi-inclusive final state $D_s^{(*)+} D_s^{(*)-}$ to be predominantly CP even and CP violation in $B_{s}^{0}$ mixing negligible, this measurement probes directly the relative decay width difference $\Delta\Gamma_{s}/\Gamma_{s}$.