The rate for e+e-→BB±π± and its implications for the study of CP violation, BS identification, and the study of B meson chiral perturbation theory

H. Yamamoto has proposed employing B-mesons produced in conjunction with a single charged pion at an ϒ resonance for studies of CP violation in the neutral B-meson system at a symmetric e+ e- collider. The sign of the charged pion would tag the neutral B-meson. We estimate this branching ratio, employing the heavy meson chiral effective field theory. We find a negligible branching ratio to BB± π∓ at the ϒ(5S) and a branching ratio of only a few percent at the ϒ(6S). However, if nonresonant studies of neutral B-mesons should prove feasible, Yamamoto's proposal could be a good method for tagging neutral B's for the study of CP violation at a symmetric collider. We also explore the possibility of studying Bs mesons at the ϒ(5S). The rate is low but depends sensitively on the precise value of the mass of the Bs. The background we compute is comparable to the rate at the largest allowed value of the Bs mass. Finally, we discuss the extraction of the axial coupling of the pion to B-mesons from measurement of the BBπ branching fraction in a restricted region of phase space, where chiral perturbation theory should work well.