학술논문
Observation of B¯→D(*) π+π-ℓ-ν¯ Decays in e+e- Collisions at the Υ(4S) Resonance
Document Type
article
Author
Lees, JP; Poireau, V; Tisserand, V; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, DN; Kerth, LT; Kolomensky, Yu G; Lee, MJ; 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, Yu I; Solodov, EP; Todyshev, K Yu; Lankford, AJ; Gary, JW; Long, O; Franco Sevilla, M; Hong, TM; Kovalskyi, D; Richman, JD; West, CA; Eisner, AM; Lockman, WS; Panduro Vazquez, W; Schumm, BA; Seiden, A; Chao, DS; Cheng, CH; Echenard, B; Flood, KT; Hitlin, DG; Kim, J; Miyashita, TS; Ongmongkolkul, P; Porter, FC; Röhrken, M; Andreassen, R; Huard, Z; Meadows, BT; Pushpawela, BG; Sokoloff, MD; Sun, L; Ford, WT; Smith, JG; Wagner, SR; Ayad, R; Toki, WH; Spaan, B; Bernard, D; Verderi, M; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Santoro, V; Calcaterra, A; de Sangro, R; Finocchiaro, G; Martellotti, S; Patteri, P; Peruzzi, IM; Piccolo, M; Zallo, A; Contri, R; Monge, MR; Passaggio, S; Patrignani, C; Bhuyan, B; Prasad, V; Adametz, A; Uwer, U; Lacker, HM; Mallik, U; Chen, C; Cochran, J; Prell, S; Ahmed, H; Gritsan, AV; Arnaud, N; Davier, M
Source
Physical Review Letters. 116(4)
Subject
Language
Abstract
We report on measurements of the decays of B¯ mesons into the semileptonic final states B¯→D^(*)π^(+)π^(-)ℓ^(-)ν¯, where D^(*) represents a D or D^(*) meson and ℓ^(-) is an electron or a muon. These measurements are based on 471×10^(6) BB ¯ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R_{π^{+}π^{-}}^{(*)}=B(B[over ¯]→D^{(*)}π^{+}π^{-}ℓ^{-}ν[over ¯])/B(B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]) using events in which the second B meson is fully reconstructed. We find R_{π^{+}π^{-}}=0.067±0.010±0.008 and R_{π^{+}π^{-}}^{*}=0.019±0.005±0.004, where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that B[over ¯]→D^{(*)}ππℓ^{-}ν[over ¯] decays, where π denotes either a π^{±} and π^{0} meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.