Observation of the decay B̄0→Λc+p̄π0

Author(s): Aubert, B; Karyotakis, Y; Lees, JP; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V; GarraTico, J; Grauges, E; Martinelli, M; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Battaglia, M; Brown, DN; Hooberman, B; Kerth, LT; Kolomensky, YG; Lynch, G; Osipenkov, IL; Tackmann, K; Tanabe, T; Hawkes, CM; Soni, N; Watson, AT; Koch, H; Schroeder, T; Asgeirsson, DJ; Hearty, C; Mattison, TS; McKenna, JA; Barrett, M; Khan, A; Randle-Conde, A; Blinov, VE; Bukin, AD; Buzykaev, AR; Druzhinin, VP; Golubev, VB; Onuchin, AP; Serednyakov, SI; Skovpen, YI; Solodov, EP; Todyshev, KY; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, AJ; Lund, P; Mandelkern, M; Martin, EC; Stoker, DP; Atmacan, H; Gary, JW; Liu, F; Long, O; Vitug, GM; Yasin, Z; Sharma, V; Campagnari, C; Hong, TM; Kovalskyi, D; Mazur, MA; Richman, JD; Beck, TW; Eisner, AM; Heusch, CA; Kroseberg, J; Lockman, WS; Martinez, AJ; Schalk, T; Schumm, BA; Seiden, A; Wang, L; Winstrom, LO; Cheng, CH; Doll, DA; Echenard, B; Fang, F; Hitlin, DG; Narsky, I; Ongmongkolkul, P | Abstract: In a sample of 467×106 BB pairs collected with the BABAR detector at the PEP-II collider at SLAC we have observed the decay B0→Λc+pπ0 and measured the branching fractionto be (1.94±0.17±0.14±0.50)×10-4, where the uncertainties are statistical, systematic, and the uncertainty on the Λc+→pK-π+ branching fraction, respectively. We determine an upper limit of 1.5×10-6 at 90% C.L. for the product branching fractionB(B0→Σc+(2455)p) ×B(Λc+→pK-π+). Furthermore, we observe an enhancement at the threshold of the invariant massof the baryon-antibaryon pair. © 2010 The American Physical Society.