We report on a study of inclusive $B^-$ and $\bar{ B}^0$ meson decays to ${ D^0 X}$, ${ \bar{ D}^0 X}$, ${ D^+ X}$, ${ D^- X}$, ${ D_s^+ X}$, ${ D_s^- X}$, ${ \Lambda_c^+ X}$, ${ \bar{ \Lambda}_c^- X}$, based on a sample of 231 million $B\bar{ B}$ events recorded with the BABAR detector at the $\Upsilon{ (4S)}$ resonance. Events are selected by completely reconstructing one $B$ and searching for a reconstructed charm particle in the rest of the event. From the measured branching fractions of these decays, we infer the number of charm and anti-charm particles per $\bar{ B}$ decay, separately for charged and neutral parents. We derive the total charm yield per $B^-$ decay, $n_c^- = 1.202 \pm 0.023\pm 0.040^{ +0.035}_{ -0.029} $, and per $\bar{ B}^0$ decay, $n_c^0 = 1.193 \pm 0.030\pm 0.034^{ +0.044}_{ -0.035}$ where the first uncertainty is statistical, the second is systematic, and the third reflects the charm branching-fraction uncertainties. We also present the charm momentum distributions measured in the $\bar{ B}$ rest frame.
Categories: hep-ex