Measurements of direct CP violating asymmetries in charmless decays of strange bottom mesons and bottom baryons

Abstract

We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1fb-1 of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, ACP(Bs0→K -π+)=+0.39±0.15(stat)±0.08(syst), and bottom baryons, ACP(Λb0→pπ-)=+0. 03±0.17(stat)±0.05(syst) and ACP(Λb0→ pK-)=+0.37±0.17(stat)±0.03(syst). In addition, we measure CP violation in B0→K+π- decays with 3.5σ significance, ACP(B0→K+π-)=- 0.086±0.023(stat)±0.009(syst), in agreement with the current world average. Measurements of branching fractions of Bs0→K+K - and B0→π+π- decays are also updated. © 2011 American Physical Society.