Measurement of the CP -Violating Phase φs in B ¯ s0 → Ds+ Ds- Decays

Abstract

We present a measurement of the CP-violating weak mixing phase φs using the decay B¯s0→Ds+Ds- in a data sample corresponding to 3.0fb-1 of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV. An analysis of the time evolution of the system, which does not use the constraint |λ|=1 to allow for the presence of CP violation in decay, yields φs=0.02±0.17(stat)±0.02(syst)rad, |λ|=0.91-0.15+0.18(stat)±0.02(syst). This result is consistent with the standard model expectation.