Search for rare quark-annihilation decays, B --> Ds(*) Phi

TL;DR

This study searches for rare B meson decays into Ds(*) Phi, setting upper limits on their branching fractions, which align with Standard Model predictions and improve constraints on such annihilation processes.

Contribution

First search for B- --> Ds(*) Phi decays, providing the most stringent upper limits to date on their branching fractions.

Findings

No evidence for the decays was observed.

Upper limits on branching fractions were set at 1.9x10^(-6) and 1.2x10^(-5).

Results are consistent with Standard Model expectations.

Abstract

We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) < 1.9x10^(-6) and BF(B- --> Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.