Study of T and CP Violation in B{sup 0}-anti-B{sup 0} Mixing with Inclusive Dilepton Events

Abstract

We report a study of T and CP violation in B{sup 0}{bar B}{sup 0} mixing using an inclusive dilepton sample collected by the BABAR experiment at the PEP-II B Factory. The asymmetry between {ell}{sup +}{ell}{sup +} and {ell}{sup -}{ell}{sup -} allows us to compare the probabilities for {bar B}{sup 0} {yields} B{sup 0} and B{sup 0} {yields} {bar B}{sup 0} oscillations and thus probe T and CP invariance. A sample of 20,381 same-sign dilepton events is selected in the 1999--2000 data sample, corresponding to an integrated luminosity of 20.7 fb{sup -1} on the {Upsilon}(4S) resonance. We measure a same-sign dilepton asymmetry of A{sub T} = (0.5 {+-} 1.2 {+-} 1.4)%; for the parameter {epsilon}{sub B} representing T and CP violations in mixing, we obtain a preliminary result of Re({epsilon}{sub B})/1 + |{epsilon}{sub B}|{sup 2} = (1.2 {+-} 2.9 {+-} 3.6) x 10{sup -3}.