Effect of direct cp violation in charm on γ extraction from [B.sup.±] → [DK.sup.±], D → [K.sup.0.sub.S][π.sup.+][π.sup.-] Dalitz plot analysis

A possible effect of direct CP violation in D → [K.sup.0.sub.S][π.sup.+][π.sup.-] decay on the y measurement from [B.sup.±] → [DK.sup.[+ or - ]], D → [K.sup.0.sub.S][π.sup.+][π.sup.-] Dalitz plot analysis is considered. Systematic uncertainty of y coming from the current limits on direct CP violation in D → [K.sup.0.sub.S][π.sup.+][π.sup.-] is estimated, and a modified model-independent procedure of [B.sup.±] - [DK.sup.±], D → [K.sup.0.sub.S][π.sup.+][π.sup.-] Dalitz plot analysis is proposed that gives an unbiased γ measurement even in presence of direct CP violation in charm decays. The technique is applicable to other threebody D decays such as [D.sup.0] → [K.sup.0.sub.S][K.sup.+][K.sup.-], [D.sup.0] → [π.sup.+][π.sup.-][π.sup.0], etc.