Measurements of ϕ1(β) in B decays to charm and charmonium at Belle

Abstract

We present a measurement of the time-dependent CP violation parameters for B0 → D*+D*-Ks0 and B0 → J/ψKs0 decays obtained from the distribution of proper time intervals between the two B decays. These results are obtained from a data sample of BB pairs collected at the γ (4S) resonance with the Belle detector at the KEKB asymmetric e+e− collider. For B0 → D*+D*-Ks0, we find no evidence for direct or mixing-induced CP violation, and in a fit sensitive to cos2ϕ1, no conclusion can be drawn regarding its sign with current statistics. For B0 → J/ψπ0, we find no evidence for direct CP violation and measure mixing-induced CP violation consistent with Standard Model expectations, with a 2.4σ significance.