Search for CP Violation in B0- ¯¯¯B0 Mixing Using Partial Reconstruction of B0→D*−Xℓ+νℓ and a Kaon Tag

Abstract

We present results of a search for C P violation in B 0 − ¯¯¯ B 0 mixing with the BABAR detector. We select a sample of B 0 → D * − X ℓ + ν decays with a partial reconstruction method and use kaon tagging to assess the flavor of the other B meson in the event. We determine the C P violating asymmetry A C P ≡ [ N ( B 0 B 0 ) − N ( ¯¯¯ B 0 ¯¯¯ B 0 ) ] / [ N ( B 0 B 0 ) + N ( ¯¯¯ B 0 ¯¯¯ B 0 ) ] = ( 0.06 ± 0.17 + 0.38 − 0.32 ) % , corresponding to Δ C P = 1 − | q / p | = ( 0.29 ± 0.84 + 1.88 − 1.61 ) × 10 − 3 .