Search for B^+ --> K^+l^+l^- and B^0 --> K^(*0)l^+l^-

TL;DR

This study searches for rare B meson decays involving K mesons and lepton pairs, setting upper limits on their branching fractions due to no significant signals observed in the data.

Contribution

First search for these specific electroweak penguin B decay modes using a large data sample, establishing upper limits on their branching fractions.

Findings

No significant signals detected for the decay modes.

Set 90% confidence level upper limits on branching fractions.

Results constrain theoretical models of rare B decays.

Abstract

Using a sample of 3.7 x 10^{6} Y(4S) --> B-anti-B events collected with the BABAR detector at the PEP-II storage ring, we search for the electroweak penguin decays B^+ --> K^+e^+e^-, B^+ --> K^+mu^+mu^-, B^0 --> K^{*0)e^+e^-, and B^0 --> K^{*0)mu^+mu^-. We observe no significant signals for these modes and set preliminary 90% C.L. upper limits of B(B^+ --> K^+e^+e^-) < 12.5 x 10^{-6}, B(B^+ --> K^+mu^+mu^-) < 8.3 x 10^{-6}, B(B^0 --> K^{*0)e^+e^-) < 24.1 x 10^{-6}, B(B^0 --> K^{*0)mu^+mu^-) < 24.5 x 10^{-6}.