The CP violation observables S and C in the decay channel B^0→D^+D^- are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb^-1. The observable S describes CP violation in the interference between mixing and the decay amplitude, and C parametrizes direct CP violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: S=-0.54_-0.16^+0.17(stat)±0.05(syst), C=0.26_-0.17^+0.18(stat)±0.02(syst). These values provide evidence for CP violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order standard model corrections is constrained to a small value of Δϕ=-0.16_-0.21^+0.19 rad.
Measurement of CP Violation in B^0→D^+D^- Decays
VELTRI, MICHELE;
2016
Abstract
The CP violation observables S and C in the decay channel B^0→D^+D^- are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb^-1. The observable S describes CP violation in the interference between mixing and the decay amplitude, and C parametrizes direct CP violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: S=-0.54_-0.16^+0.17(stat)±0.05(syst), C=0.26_-0.17^+0.18(stat)±0.02(syst). These values provide evidence for CP violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order standard model corrections is constrained to a small value of Δϕ=-0.16_-0.21^+0.19 rad.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
