Measurement of the CKM angle γ from a combination of B±→Dh± analyses

Abstract

A combination of three LHCb measurements of the CKM angle gamma is presented. The decays B-+/- -> DK +/- and B-+/- -> D pi(+/-) are used, where D denotes an admixture of D-0 and (D) over bar (0) mesons, decaying into K+K-, pi(+)pi(-), K-+/-pi(-/+), K-+/-pi(-/+)pi(+/-)pi(-/+), or K-S(0)pi(+)pi(-) final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B-+/- -> DK +/- Dill decays alone a best-fit value of gamma = 72.0 degrees is found, and confidence intervals are set gamma is an element of [56.4, 86.7]degrees at 68% CL, gamma is an element of [42.6, 99.6]degrees at 95% CL. The best-fit value of gamma found from a combination of results from B-+/- -> D pi(+/-) decays alone, is gamma = 18.9 degrees, and the confidence intervals gamma is an element of [7.4, 99.2]degrees boolean OR [167.9, 176.4]degrees at 68% CL are set, without constraint at 95% CL The combination of results from B1 DKI and B -> DTC decays gives a best-fit value of y = 72.6 degrees and the confidence intervals gamma is an element of [55.4, 82.3]degrees at 68% CL, gamma is an element of [40.2, 92.7]degrees at 95% CL are set. All values are expressed modulo 180 degrees, and are obtained taking into account the effect of D-0-(D) over bar (0) mixing.