Search for the rare decaysB→πℓ+ℓ−andB0→ηℓ+ℓ−

Author(s): Lees, JP; Poireau, V; Tisserand, V; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, DN; Kerth, LT; Kolomensky, YG; Lynch, G; Koch, H; Schroeder, T; Hearty, C; Mattison, TS; McKenna, JA; So, RY; Khan, A; Blinov, VE; Buzykaev, AR; Druzhinin, VP; Golubev, VB; Kravchenko, EA; Onuchin, AP; Serednyakov, SI; Skovpen, YI; Solodov, EP; Todyshev, KY; Yushkov, AN; Kirkby, D; Lankford, AJ; Mandelkern, M; Dey, B; Gary, JW; Long, O; Vitug, GM; Campagnari, C; Franco Sevilla, M; Hong, TM; Kovalskyi, D; Richman, JD; West, CA; Eisner, AM; Lockman, WS; Martinez, AJ; Schumm, BA; Seiden, A; Chao, DS; Cheng, CH; Echenard, B; Flood, KT; Hitlin, DG; Ongmongkolkul, P; Porter, FC; Andreassen, R; Huard, Z; Meadows, BT; Sokoloff, MD; Sun, L; Bloom, PC; Ford, WT; Gaz, A; Nauenberg, U; Smith, JG; Wagner, SR; Ayad, R; Toki, WH; Spaan, B; Schubert, KR; Schwierz, R; Bernard, D; Verderi, M; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R | 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)→BB 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 -)l5.9×10-8 and a lepton-flavor averaged upper limit of B(B0→ηl+l-)l6.4×10 -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.