Search for the rare decays B→πℓ+ℓ- and B0→ηℓ+ℓ-

Abstract

We present the results of a search for the rare flavor-changing neutral-current decays B→πℓ+ℓ- (π=π±, π0 and ℓ=e, μ) and B0→ηℓ +ℓ- using a sample of e+e -→Υ(4S)→BB̄ decays corresponding to 428 fb -1 of integrated luminosity collected by the BABAR detector. No significant signal is observed, and we set an upper limit on the isospin and lepton-flavor averaged branching fraction of B(B→πℓ+ℓ -)<5.9×10-8 and a lepton-flavor averaged upper limit of B(B0→ηℓ+ℓ-)<6.4×10 -8, both at the 90% confidence level. We also report 90% confidence level branching fraction upper limits for the individual modes B +→π+e+e-, B0→π0e+e-, B+→π+μ +μ-, B0→π0μ+μ-, B0→ηe+e-, and B0→ημ+μ -. © 2013 American Physical Society.