학술논문
Measurement of the B→Xsℓ+ℓ- Branching Fraction and Search for Direct CP Violation from a Sum of Exclusive Final States
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; Yushkov, AN; Lankford, AJ; Mandelkern, M; Dey, B; Gary, JW; Long, O; Campagnari, C; Sevilla, M Franco; Hong, TM; Kovalskyi, D; Richman, JD; West, CA; Eisner, AM; Lockman, WS; Schumm, BA; Seiden, A; Chao, DS; Cheng, CH; Echenard, B; Flood, KT; Hitlin, DG; Miyashita, TS; Ongmongkolkul, P; Porter, FC; Andreassen, R; Huard, Z; Meadows, BT; Pushpawela, BG; Sokoloff, MD; Sun, L; Bloom, PC; Ford, WT; Gaz, A; Nauenberg, U; Smith, JG; Wagner, SR; Ayad, R; Toki, WH; Spaan, B; 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; Calcaterra, A; de Sangro, R; Finocchiaro, G; Martellotti, S; Patteri, P; Peruzzi, IM; Piccolo, M; Rama, M; Zallo, A; Contri, R; Guido, E; Vetere, M Lo; Monge, MR; Passaggio, S; Patrignani, C; Robutti, E; Bhuyan, B; Prasad, V; Morii, M
Source
Physical Review Letters. 112(21)
Subject
Language
Abstract
We measure the total branching fraction of the flavor-changing neutral-current process B→Xℓ+ℓ-, along with partial branching fractions in bins of dilepton and hadronic system (Xs) mass, using a sample of 471×106 (4S)→BB̄ events recorded with the BABAR detector. The admixture of charged and neutral B mesons produced at PEP-II2 are reconstructed by combining a dilepton pair with 10 different Xs final states. Extrapolating from a sum over these exclusive modes, we measure a lepton-flavor-averaged inclusive branching fraction B(B→Xℓ+ℓ-)=[6.73-0.64+0.70(stat)-0. 25+0.34(exp syst)±0.50(model syst)]×10-6 for mℓ+ℓ-2>0. 1GeV2/c4. Restricting our analysis exclusively to final states from which a decaying B meson's flavor can be inferred, we additionally report measurements of the direct CP asymmetry ACP in bins of dilepton mass; over the full dilepton mass range, we find ACP=0.04±0.11±0.01 for a lepton-flavor- averaged sample. © 2014 American Physical Society.