Measurement of branching fractions and search for CP-violating charge asymmetries in charmless two-body B decays into pions and kaons

We present measurements, based on a sample of approximately 23 x 10(6) B (B) over bar pairs, of the branching fractions and a search for CP-violating charge asymmetries in charmless hadronic decays of B mesons into two-body final states of kaons and pions. We find the branching fractions B(B-0--> pi (+)pi (-)) = (4.1 +/-1.0 +/-0.7) x 10(-6), B(B-0--> K(+)pi (-)) = (16.7 +/-1.6 +/-1.3) x 10(-6), B (B+-->K(+)pi (0)) = (10.8(-1.9)(+2.1)+/-1.0) x 10(-6), B(B+-->K(0)pi (+)) = (18.2(-3.0)(+3.3)+/-2.0) x 10(-6), B(B-0-->K(0)pi (0)) = (8.2(-2.7)(+3.1)+/-1.2) x 10(-6). We also report 90% confidence level upper limits for B meson decays to the pi (+)pi (0), K+K-, and (K) over bar K-0(+) final states. In addition, charge asymmetries have been found to be consistent with zero, where the statistical precision is in the range of +/-0.10 to +/-0.18, depending on the decay mode.