Observations of π-B charge-flavor correlations and resonant Bπ and BK production

Evidence is presented for kinematic and charge correlations of B mesons with charged pions and kaons. Using a new technique, a sample of over 80 000 partially reconstructed B mesons is obtained in 3.5·10⁶ hadronic Z⁰ decays recorded using the OPAL detector at LEP. The invariant mass distributions of B⁺π^- and B⁺K^- combinations show enhancements consistent with the decays of P-wave resonances of a b antiquark and a light quark. We observe an excess of 1738±195 B⁺π^- pairs with invariant masses in the range 5.60-5.85 GeV and an excess of 149±31 B⁺K^- pairs with invariant masses in the range 5.80-6.00 GeV. Labeling the observed enhancements generically as B^** we find {Mathematical expression} where B^(*)+ indicates the sum of B⁺ and B^*+ and the errors include statistical and systematic contributions. From a study of π-B charge-flavor correlations we conclude that the production flavor of a B meson can be tagged with the charge of a pion in an appropriately chosen kinematic region, and that the performance of this flavor tag compares favorably in the {Mathematical expression} environment with lepton-based tags.