Measurements of Branching Fractions for B0 --> Ds+pi- and B0-bar --> Ds+K-

TL;DR

This paper reports precise measurements of specific B0 meson decay branching fractions and the amplitude ratio between suppressed and favored decay modes, providing insights into weak decay processes.

Contribution

The study provides improved measurements of B0 decay branching fractions and the amplitude ratio, enhancing understanding of B meson decay dynamics.

Findings

BF(B0 --> Ds+pi-) = (1.99 +/- 0.26 +/- 0.18) x 10^-5

BF(B0-bar --> Ds+K-) = (1.91 +/- 0.24 +/- 0.17) x 10^-5

R_Dpi = (1.71 +/- 0.11 +/- 0.09 +/- 0.02)%

Abstract

We present improved measurements of the branching fractions for the decays B0 --> Ds+pi- and B0-bar --> Ds+K- using a data sample of 657x10^6 BB-bar events collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. The results are BF(B0 --> Ds+pi-) = (1.99 +/- 0.26 +/- 0.18)x10^-5 and BF(B0-bar --> Ds+K-) = (1.91 +/- 0.24 +/- 0.17)x10^-5, where the uncertainties are statistical and systematic, respectively. Based on these results, we determine the ratio between amplitudes of the doubly Cabibbo suppressed decay B0 --> D+pi- and the Cabibbo favored decay B0 --> D-pi+, R_Dpi = [1.71 +/- 0.11(stat) +/- 0.09(syst) +/- 0.02(theo)]%, where the last term denotes the theory error.