Search for the lepton-flavor-violating decay B0→K*0μ±e∓

Abstract

We have searched for the lepton-flavor-violating decay B0→K*0μ±e∓ using a data sample of 711 fb−1 that contains 772×106 B¯B pairs. The data were collected near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. No signals were observed, and we set 90% confidence level upper limits on the branching fractions of B(B0→K*0μ+e−)<1.2×10−7, B(B0→K*0μ−e+)<1.6×10−7, and, for both decays combined, B(B0→K*0μ±e∓)<1.8×10−7. These are the most stringent limits on these decays to date.