Measurements of Branching Fractions and Time-dependent CP Violating Asymmetries in $B{0} \to D{(*)\pm}D{\mp}$ Decays.

Abstract

Wereportmeasurementsofbranchingfractionsandtime-dependentCPasymmetriesinB0!D+D?andB0!DDdecaysusingadatasamplethatcontains(77211)106BB pairscollectedatthe(4S)resonancewiththeBelledetectorattheKEKBasymmetric-energye+e? collider.WedeterminethebranchingfractionstobeB ? B0!D+D? =(2:120:160:18)10?4 andB ?B0!DD =(6:140:290:50)10?4.WemeasureCPasymmetryparameters SD+D?=?1:06+0:21 ?0:140:08andCD+D?=?0:430:160:05inB0!D+D?andADD=+0:06 0:050:02,SDD=?0:780:150:05,CDD=?0:010:110:04,SDD=?0:130:150:04andCDD=+0:120:110:03inB0!DD,wheretherstuncertaintyisstatisticaland thesecondissystematic.WeexcludetheconservationofCPsymmetryinbothdecaysatequalto orgreaterthan4signicance.