학술논문
Measurement of CP asymmetries and branching fractions in charmless two-body B-meson decays to pions and kaons
Document Type
article
Author
Lees, JP; Poireau, V; Tisserand, V; Garra Tico, J; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, DN; Kerth, LT; Kolomensky, YG; Lynch, G; Koch, H; Schroeder, T; Asgeirsson, DJ; 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; Bondioli, M; Kirkby, D; Lankford, AJ; Mandelkern, M; Atmacan, H; Gary, JW; Liu, F; Long, O; Vitug, GM; Campagnari, C; Hong, TM; Kovalskyi, D; Richman, JD; West, CA; Eisner, AM; Kroseberg, J; Lockman, WS; Martinez, AJ; Schumm, BA; Seiden, A; Chao, DS; Cheng, CH; Echenard, B; Flood, KT; Hitlin, DG; Ongmongkolkul, P; Porter, FC; Rakitin, AY; 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; Clark, PJ; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Munerato, M; Negrini, M; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, IM; Piccolo, M; Rama, M; Zallo, A; Contri, R
Source
Physical Review D - Particles, Fields, Gravitation and Cosmology. 87(5)
Subject
Language
Abstract
We present improved measurements of CP-violation parameters in the decays B0→π+π-, B0→K+π-, and B0→π0π0, and of the branching fractions for B0→π0π0 and B0→K0π0. The results are obtained with the full data set collected at the Υ(4S) resonance by the BABAR experiment at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, corresponding to (467±5)×106 BB̄ pairs. We find the CP-violation parameter values and branching fractions: Sπ+π-=- 0.68±0.10±0.03, Cπ+π-=-0.25±0.08±0. 02, AK-π+=-0.107±0.016-0.004+0.006, C π0π0=-0.43±0.26±0.05, B(B0→π0π0)=(1. 83±0.21±0.13)×10-6, B(B0→K0π0)=(10. 1±0.6±0.4)×10-6, where in each case, the first uncertainties are statistical and the second are systematic. We observe CP violation with a significance of 6.7 standard deviations for B0→π+π- and 6.1 standard deviations for B0→K+π-, including systematic uncertainties. Constraints on the unitarity triangle angle α are determined from the isospin relations among the B→ππ rates and asymmetries. Considering only the solution preferred by the Standard Model, we find α to be in the range [71, 109] at the 68% confidence level. © 2013 American Physical Society.