Measurements of branching fraction ratios andCP-asymmetries in suppressedB−→D(→K+π−)K−andB−→D(→K+π−)π−decays

We report the first reconstruction in hadron collisions of the suppressed decays B-→ D(→ K+π-)K- and B-→ D(→ K+π-)π- decays, sensitive to the CKM phase {gamma}, using data from 7 fb-1 of integrated luminosity collected by the CDF II detector at the Tevatron collider. We reconstruct a signal for the B-→ D(→ K+π-)K- suppressed mode with a significance of 3.2 standard deviations, and measure the ratios of the suppressed to favored branching fractions R(K) = [22.0 ± 8.6(stat) ± 2.6(syst)] x 10-3, R+(K) = [42.6 ± 13.7(stat) ± 2.8(syst)] x 10-3, R-(K) = [3.8 ± 10.3(stat) ± 2.7(syst)] x 10-3 as well as the direct CP-violating asymmetry A(K) = -0.82±0.44(stat)±0.09(syst) of this mode. Corresponding quantities for B- → D(→ K+π-)π- decay are also reported.