Measurement ofϕ3with Dalitz plot analysis ofB±→D(*)K±decay

We present a measurement of the unitarity triangle angle {phi}{sub 3} using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B{sup {+-}}{yields}D{sup (*)}K{sup {+-}} process. The method employs the interference between D{sup 0} and D{sup 0} to extract both the weak and strong phases. We apply this method to a 140 fb{sup -1} data sample collected by the Belle experiment. The analysis uses the modes B{sup {+-}}{yields}DK{sup {+-}} and B{sup {+-}}{yields}D*K{sup {+-}}, D*{yields}D{pi}{sup 0}, where the neutral D meson decays into K{sub S}{pi}{sup +}{pi}{sup -}. We obtain 146 signal candidates for B{sup {+-}}{yields}DK{sup {+-}} and 39 candidates for B{sup {+-}}{yields}D*K{sup {+-}}. From a combined maximum likelihood fit to the B{sup {+-}}{yields}DK{sup {+-}} and B{sup {+-}}{yields}D*K{sup {+-}} modes, we obtain {phi}{sub 3}=77 deg. (+17 deg./-19 deg.)(stat){+-}13 deg. (syst){+-}11 deg. (model). The corresponding 2 standard deviation interval is 26 deg.