Inclusive /b decays to wrong sign charmed mesons

The production of wrong sign charmed mesons b-->D_(s)X, D_(s)=(D⁰,D⁺,D_s), is studied using the data collected by the DELPHI experiment in the years 1994 and 1995.

Charmed mesons in /Z-->bb¯ events are exclusively reconstructed by searching for the decays D⁰-->K^-π⁺, D⁺-->K^-π⁺π⁺ and D_s⁺-->φπ⁺-->K⁺K^-π⁺. The wrong sign contribution is extracted by using two discriminant variables: the charge of the /b-quark at decay time, estimated from the charges of identified particles, and the momentum of the charmed meson in the rest frame of the /b-hadron.

The inclusive branching fractions of /b-hadrons into wrong sign charm mesons are measured to be: B(b-->D⁰X)+B(b-->D^-X)=(9.3+/-1.7(stat)+/-1.3(syst)+/-0.4(B))%, B(b-->D_s^-X)=(10.1+/-1.0(stat)+/-0.6(syst)+/-2.8(B))% where the first error is statistical, the second and third errors are systematic.