CP violation studies in B0 → D(*)±π-+ in BABAR and Belle

We present a preliminary measurement of the time-dependent CP asymmetries in decays of B0 mesons to the final states D(*)π using data collected by the BABAR experiment at the PEP-II storage rings. B mesons decaying to Dπ are fully reconstructed, while events containing B → D*π are selected using a full or a partial reconstruction technique. These results can be interpreted in terms of a constraint on the angles of the unitarity triangle to set a lower bound on |sin(2β + γ)|. The Belle experiment at the KEK - B collider is performing the same kind of studies and a preliminary estimation of the achievable error is presented. (author)