Evidence of time-dependent CP violation in the decay B^{0}→D^{*+}D^{*-}

We report a measurement of the CP-odd fraction and the time-dependent CP violation in B-0 -> D*+D*- decays, using 657x10(6) BB events collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We measure a CP-odd fraction of R-perpendicular to=0.125 +/- 0.043(stat)+/- 0.023(syst). From the distributions of the proper-time intervals between a B-0 -> D*+D*- decay and the other B meson in the event, we obtain evidence of CP violation with measured parameters A(D)(+)D(-)=0.15 +/- 0.13(stat)+/- 0.04(syst) and SD*+D*-=-0.96 +/- 0.25(stat)(-0.16)(+0.13)(syst).