Charge asymmetry of same-sign dileptons in B0-B-0 mixing

We report a measurement of the charge asymmetry for same-sign dileptons in B-0-(B) over bar (0) mixing, A(sl). The data were collected with the Belle detector at KEKB. Using a data sample of 78 fb(-1) recorded at the Upsilon(4S) resonance and 9 fb(-1) recorded at an energy 60 MeV below the resonance, we measure A(sl)=(-1.1 +/- 7.9(stat)+/- 8.5(sys))x10(-3).