Abstract

A binned Dalitz plot analysis of B-+/- -> DK +/- decays, with D -> K-0(S)pi(+)pi(-) and D -> (KSK+K-)-K-0 is performed to measure the CP-violating observables x(+/-) and y(+/-) which are sensitive to the CKM angle y. The analysis exploits 1.0 fb(-1) of data collected by the LHCb experiment. The study makes no model-based assumption on the variation of the strong phase of the D decay amplitude over the Dalitz plot, but uses measurements of this quantity from CLEO-c as input. The values of the parameters are found to be x_ = (0.0 +/- 4.3 1.5 +/- 0.6) x 10(-2), y_ = (2.7 +/- 5.2 +/- 0.8 +/- 2.3) x 10-2, x(+) =(-10.3 +/- 4.5 +/- 1.8 +/- 1.4) x 10-2 and y(+) = (-0.9 +/- 3.7 0.8 +/- 3.0) x 10-2. The first, second, and third uncertainties are the statistical, the experimental systematic, and the error associated with the precision of the strong-phase parameters measured at CLEO-c, respectively. These results correspond to gamma = (44(-38)(+43))degrees, with a second solution at gamma -> gamma + 180 degrees and r(B) = 0.07 +/- 0.04, where r(B) is the ratio between the suppressed and favoured B decay amplitudes. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.

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