A model-independent Dalitz plot analysis of B^±→DK^± with D→KS0h+h- (h=π, K) decays and constraints on the CKM angle γ

A binned Dalitz plot analysis of B ^±→DK ^± decays, with D→KS0π+π- and D→KS0K+K-, is performed to measure the CP-violating observables x _± and y _± which are sensitive to the CKM angle γ. 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)×10 ^-2, y _-=(2.7±5.2±0.8±2.3)×10 ^-2, x ₊=(-10.3±4.5±1.8±1.4)×10 ^-2 and y ₊=(-0.9±3.7±0.8±3.0)×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 γ=(44-38+43)°, with a second solution at γ→γ+180°, and r _B=0.07±0.04, where r _B is the ratio between the suppressed and favoured B decay amplitudes.