Measurement of CP violation and constraints on the CKM angle γ in B±→DK±with D→K0S π+π− decays

Abstract

A model-dependent amplitude analysis of B± → DK± with D → KS0π+π− decays is performed using proton–proton collision data, corresponding to an integrated luminosity of 1fb−1, recorded by LHCb at a centre-of-mass energy of 7TeV in 2011. Values of the CP violation observables x± and y±, which are sensitive to the CKM angle γ, are measured to be x− =+0.027 ± 0.044+−00..010008 ± 0.001, y− =+0.013 ± 0.048+−00..009007 ± 0.003, x+ =−0.084 ± 0.045 ± 0.009 ± 0.005, y+ =−0.032 ± 0.048+−00..010009 ± 0.008, the D → KS0π+π− amplitude model. The value of γ is determined to be (84−4942)◦, including all sources of uncertainty. Neutral D meson mixing is found to have negligible effect. where the first uncertainty is statistical, the second systematic and the third arises from the uncertainty of