Measurements of branching fractions and CP-violating asymmetries in B0 -> pi+pi-, K+pi-, K+K- decays

Abstract

We present updated measurements of branching fractions and CP-violating asymmetries for neutral B meson decays to two-body final states of charged pions and kaons. The results are obtained from a data sample of about 60 million Y(4S) to BB decays collected between 1999 and 2001 by the BaBar detector at the Pep-II asymmetric-energy B Factory at SLAC. The sample contains 124+16-15 pipi, 403+-24 Kpi, and 1+8-7 KK candidates, from which we measure the following quantities: B(B0 -> pi+pi-) = (5.4 +- 0.7 +- 0.4) x 10^(-6) B(B0 -> K+pi-) = (17.8 +- 1.1 +- 0.8) x 10^(-6) B(B0 -> K+K-) < 1.1 x 10^-6 (90% C.L.) Kpi asymmetry = -0.05 +- 0.06 +- 0.01, 90% C.L. [-0.14, +0.05] Spipi = -0.01 +- 0.37 +- 0.07, 90% C.L. [-0.66, +0.62] Cpipi = -0.02 +- 0.29 +- 0.07, 90% C.L. [-0.54, +0.48] where the errors are statistical and systematic, respectively. These results are preliminary.