Measurement Of The Time-dependent Cp Asymmetries In B~0 → K_s~0ρ~0γ Decays

摘要

We report the first measurement of time-dependent CP asymmetry in B~0 → K_s~0ρ~0γ decays based on 657 × 10~6 BB pairs collected with the Belle detector at the KEKB asymmetric-energy collider. We measure the CP-violating parameter S_(K_s~0ρ~0γ) = 0.11 ± 0.33(stat)_(-0.09)~(+0.05)(syst) from a signal of 212 ± 17 events. We also obtain the effective direct CP-violating parameter A_(eff) = 0.05 ± 0.18(stat) ± 0.06(syst) for m_(K_s~0π~+π~-) < 1.8 GeV/c~2 and 0.6 GeV/c~2 < m_(π~+π~-) < 0.9 GeV/c~2.