A Study of The Rare Decays B0 -> Ds(*)+ pi- and B0 -> Ds(*)-K+

TL;DR

This paper reports evidence and measurements for rare B0 meson decays into Ds(*)+ pi- and Ds(*)- K+ using data from the BABAR detector, including branching fractions and upper limits.

Contribution

First evidence for B0 -> Ds+ pi- and B0 -> Ds- K+ decays with measured branching fractions, and new upper limits for B0 -> Ds*+ pi- and B0 -> Ds*- K+ decays.

Findings

Measured Br(B0 -> Ds+ pi-) = (3.2 +- 0.9 +- 1.0) x 10^-5

Measured Br(B0 -> Ds- K+) = (3.2 +- 1.0 +- 1.0) x 10^-5

Set upper limits for B0 -> Ds*+ pi- and B0 -> Ds*- K+ decays

Abstract

We report on the evidence for the decays B0 -> Ds+ pi- and B0 -> Ds- K+ and the results of a search for the decays B0 -> Ds*+ pi- and B0 -> Ds*-K+ from a sample of 84 million Upsilon(4S) decays into B meson pairs collected with the BABAR detector at the PEP II asymmetric-energy e^{+}e^{-} collider. The measured B0 -> Ds+ pi- yield has a probability of less than 10^{-3} to be a fluctuation of the background and we measure the branching fraction Br(B0 -> Ds+ pi-) = (3.2 +- 0.9 (stat) +- 1.0 (syst)) x 10^-5. The measured B0 -> Ds- K+ yield has a probability of less than 5 times 10^{-4} to be a fluctuation of the background and we measure the branching fraction Br(B0 -> Ds- K+) = (3.2 +- 1.0 (stat) +- 1.0 (syst)) x 10^-5. We also set 90% C.L. limits Br(B0 -> Ds*+ pi-)< 4.1 x 10^-5 and Br(B0 -> Ds*- K+) < 2.5 x 10^-5. All results are preliminary