Eur. Phys. J. C 23, 437-454 (2002)
https://doi.org/10.1007/s100520200892

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

Received: 24 September 2001
Published online: 1 March 2002

Abstract

From about 4 million hadronic Z⁰ decays recorded by the OPAL detector on and near to the Z⁰ resonance, we select a sample of more than 570 000 inclusively reconstructed B mesons. Orbitally-excited mesons B^*_J are reconstructed using Bπ^± combinations. Independently, B^* mesons are reconstructed using the decay B^* → Bγ. The selected B^* candidates are used to obtain samples enriched or depleted in the decay B^*_J → B^* π^±(X), where (X) refers to decay modes with or without additional accompanying decay particles. From the number of signal candidates in the Bπ^± mass spectra of these two samples, we perform the first measurement of the branching ratio of orbitally-excited B mesons decaying into B^*π(X): BR(B^*_J → B^*π(X)) = 0.85^+0.26_-0.27 ± 0.12, where the first error is statistical and the second systematic.