Search for D-0-D-0(-) mixing in D-0 -> K+pi(-) decays and measurement of the doubly-Cabibbo-suppressed decay rate

We have searched for mixing in the Ddegrees-(D) over cap (0) D-0 system by measuring the decay-time distribution of D0 ! K(+)pi(-) decays. The analysis uses 90 fb(-1) of data collected by the Belle detector at the KEKB e(+) e(-) collider. We fit the decay-time distribution for the mixing parameters x(1) and y(1) and also for the parameter R-D, which is the ratio of the rate for the doubly-Cabibbo-suppressed decay D-0--> K(+)pi(-) to that for the Cabibbo-favored decay D-0 --> K- pi(+). We do these fits both assuming CP conservation and allowing for CP violation. We use a frequentist method to obtain a 95% C. L. region in the x(J2)- y(l) plane. Assuming no mixing, we measure R-D=(0: 381 +/- 0: 017 (+) (0.008)(-0.016))%

Observation of (B)over-bar(0) -> D-sJ(*) (2317)K-+(-) decay

The decays (B) over bar (0) --> DsJ+K- and (B) over bar (0) --> D(sJ)(-)pi(+) are studied for the first time. A significant signal is observed in the (B) over bar0 --> D-sJ(*) (2317)(+) K- decay channel with B((B) over bar (0) --> D-sJ(*)(2317)K-+(-)) x B(D-sJ(*)(2317)(+) --> D(s)(+)pi(0)) = (5.3(-1.3)(+1.5) +/- 0.7 +/- 1.4) x 10(-5). No signals are observed in the (B) over bar (0) --> D-sJ(*) (2317)(-) pi(+), (B) over bar (0) --> D-sJ(2460)(+) K-, and (B) over bar (0) --> D-sJ(2460)(-) pi(+) decay modes, and upper limits are obtained. The analysis is based on a data set of 140 fb(-1) collected by the Belle experiment at the asymmetric e(+)e(-) collider KEKB

Determination of parallel to V-ub parallel to from measurements of the inclusive charmless semileptonic partial rates of B mesons using full reconstruction tags

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element parallel to V(ub)parallel to, based on 253 fb(-1) of data collected by the Belle detector at the KEKB e(+)e(-) asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Upsilon(4S). The signal for b -> u semileptonic decay is distinguished from the b -> c background using the hadronic mass M-X, the leptonic invariant mass squared q(2) and the variable P(+)equivalent to E-X-parallel to p ->(X)parallel to. The results are obtained for events with p(center dot)(*)>= 1 GeV/c, in three kinematic regions (1) M-X 8 GeV2/c(2), and by (3) P+< 0.66 GeV/c. The matrix element parallel to V(ub)parallel to is found to be (4.09 +/- 0.19 +/- 0.20(-0.15)(+0.14)+/- 0.18)x10(-3), where the errors are statistical, systematic including Monte Carlo modeling, theoretical, and from shape function parameter determination, respectively

Study of the suppressed decays B-->[K+pi(-)](D)K- and B-->[K+pi(-)](D)pi(-) - art. no. 09160

We report a study of the suppressed decays B- -> [K(+)pi(-)](D)K- and B- -> [K+ pi(-)](D)pi(-), where [K+ pi(-)](D) indicates that the K(+)pi(-) pair originates from a neutral D meson. These decay modes are sensitive to the unitarity triangle angle phi(3). We use a data sample containing 275x10(6) B (B) over bar pairs recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) storage ring. The signal for B- -> [K+ pi(-)](D)K- is not statistically significant, and we set a limit r(B) (D) over bar K-0(-))/A(B- -> (DK-)-K-0)vertical bar. We observe a signal with 6.4 sigma statistical significance in the related mode, B- -> [K(+)pi(-)](D)pi(-)