Measurement of b-hadron branching fractions fortwo-body decays into charmless charged hadrons

Abstract

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+0.008−0.007±0.009,(fs/fd)⋅B(B0s→π+π−)/B(B0→π+π−)=0.050+0.011−0.009±0.004,B(Λ0b→pπ−)/B(Λ0b→pK−)=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 f s /f d measured by LHCb, we obtain: $ B(B0→π+π−)=(5.08±0.17±0.37)×10−6,B(B0s→K+K−)=(23.0±0.7±2.3)×10−6,B(B0s→π+K−)=(5.4±0.4±0.6)×10−6,B(B0→K+K−)=(0.11+0.05−0.04±0.06)×10−6,B(B0s→π+π−)=(0.95+0.21−0.17±0.13)×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.