Investigation of the decay of orbitally-excited B mesons and first measurement of the branching ratio BR(BJ* → B*π(X))

From about 4 million hadronic Z(0) decays recorded by the OPAL detector on and near to the Z(0) resonance, we select a sample of more than 570 000 inclusively reconstructed B mesons. Orbitally-excited mesons B are reconstructed using Bpi(+/-) combinations. Independently, B-* mesons are reconstructed using the decay B-* --> Bgamma. The selected B-* candidates are used to obtain samples enriched or depleted in the decay B-J(*) --> B(*)pi(+/-)(X), where (X) refers to decay modes with or without additional accompanying decay particles. From the number of signal candidates in the Bpi(+/-) mass spectra of these two samples, we perform the first measurement of the branching ratio of orbitally-excited B mesons decaying into B* T(X): BR(B-J(*) --> B(*)pi(X)) = 0.85(-0.27)(+0.26)+/-0.12, where the first error is statistical and the second systematic.