Measurement of b-Hadron Branching Fractions for Two-Body Decays into Charmless Charged Hadrons

Based on data corresponding to an integrated luminosity of 0.37 fb−1 collected by the LHCb experiment in 2011, the following ratios of branching fractions are measured: B(B0 → π+ π−)/B(B0 → K+ π−) = 0.262 ± 0.009 ± 0.017, (fs/fd) · B(B0s → K+ K−) / B(B0 → K+ π−) = 0.316 ± 0.009 ± 0.019, (fs/fd) · B(B0s → π+ K−) / B(B0 → K+ π−) = 0.074 ± 0.006 ± 0.006, (fd/fs) · B(B0 → K+ K−) / B(B0s → K+ K−) = 0.018 (−0.007)(+0.008) ± 0.009, (fs/fd) · B(B0s → π+ π−) / B(B0 → π+ π−) = 0.050 (−0.009)(+0.011) ± 0.004, B(Λ0b → p π−) / B(Λ0b → p K−) = 0.86 ± 0.08 ± 0.05, where the first uncertainties are statistical and the second systematic. Using the current world average of B(B0 → K+ π−) and the ratio of the strange to light neutral B meson production fs/fd measured by LHCb, we obtain: B(B0 → π+ π−) = (5.08 ± 0.17 ± 0.37) x 10^−6, B(B0s → K+ K−) = (23.0 ± 0.7 ± 2.3) x 10^−6, B(B0s → π+ K−) = (5.4 ± 0.4 ± 0.6) x 10^−6, B(B0 → K+ K−) = (0.11 (−0.04)(+0.05) ± 0.06) x 10^−6, B(B0 → π+ π−) = (0.95 (−0.17)(+0.21) ± 0.13) x 10^−6. The measurements of B(B0s → K+ K−), B(B0s → π+ K−) and B(B0 → K+ K−) are the most precise to date. The decay mode B0s → π+ π− is observed for the first time with a significance of more than 5σ.