The relative abundance of the three decay modes $B_d to D^- K^+$, $B_d to D^- pi^+$ and $B_s to D_s^- pi^+$ produced in 7 TeV $pp$ collisions at the LHC is determined from data corresponding to an integrated luminosity of 35 pb$^{-1}$. The branching fraction of $B_d to D^- K^+$ is found to be $cal B (B_d to D^- K^+) = (2.01 pm 0.18^{textrm{stat}} pm 0.14^{textrm{syst}})times 10^{-4}$. The ratio of fragmentation fractions fsfdt is determined through the relative abundance of $B_s to D_s^- pi^+$ to $B_d to D^- K^+$ and $B_d to D^-pi^+$, leading to $f_s/f_d = 0.253 pm 0.017 pm 0.017 pm 0.020$, where the uncertainties are statistical, systematic, and theoretical respectively.
تحميل البحث