Measurement of branching fraction and time-dependent CP asymmetry parameters in B{sup 0}{yields}D*{sup +}D*{sup -}K{sub S}{sup 0} decays

We present a measurement of the branching fraction and time-dependent CP violation parameters for B{sup 0}{yields}D*{sup +}D*{sup -}K{sub S}{sup 0} decays. These results are obtained from a 414 fb{sup -1} data sample that contains 449x10{sup 6} BB pairs collected at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider. We obtain the branching fraction, B(B{sup 0}{yields}D*{sup +}D*{sup -}K{sub S}{sup 0})=[3.4{+-}0.4(stat){+-}0.7(syst)]x10{sup -3}, which is in agreement with the current world average. We also obtain an upper limit on the product branching fraction for a possible two-body decay, B(B{sup 0}{yields}D{sub s1}{sup +}(2536)D*{sup -})B(D{sub s1}{sup +}(2536){yields}D*{sup +}K{sub S}{sup 0}) s{sup +}, where s{sup {+-}}{identical_to}m{sup 2}(D*{sup {+-}}K{sub S}{sup 0}), we extract the CP violation parameters, J{sub c}/J{sub 0}=0.60{sub -0.28}{sup +0.25}(stat){+-}0.08(syst), 2J{sub s1}/J{sub 0}sin2{phi}{sub 1}=-0.17{sub -0.42}{sup +0.42}(stat){+-}0.09(syst), 2J{sub s2}/J{sub 0}cos2{phi}{sub 1}=-0.23{sub -0.41}{sup +0.43}(stat){+-}0.13(syst). A large value of J{sub c}/J{sub 0} would indicate a significant resonant contributionmore » from a broad unknown D{sub s}**{sup +} state. Although the sign of the factor, 2J{sub s2}/J{sub 0}, can be deduced from theory, no conclusion can be drawn regarding the sign of cos2{phi}{sub 1} given the errors.« less