Measurement of the Branching Fraction and CP Content for the Decay B (sup o) yields D (sup asterisk +) D (sup asterisk -)

摘要

We report a measurement of the branching fraction of the decay B (sup o) yields D (sup asterisk +) D (sup asterisk -) and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4 fb to the minus 1 power collected at the gamma(4S) resonance during 1999-2000, we have reconstructed 38 candidate signal events in the mode B (sup o) yields D (sup asterisk +) D (sup asterisk -) with an estimated background of 6.2 + or - 0.5 events. From these events, we determine the branching fraction to be beta B (sup o) yields D (sup asterisk +) D (sup asterisk -) = (8.3+ or -1.6(stat) + or - 1.2(syst)) X 10 to the minus 4th power. The measured CP-odd fraction of the final state is 0.22 + or - 0.18(stat) + or - 0.03(syst).