Search for B+ -> K+ l+ l- and B0 -> K*0 l+ l-

TL;DR

This study searched for rare B meson decays involving K and K* mesons with lepton pairs, using BaBar data, but found no significant signals and set upper limits on their branching fractions.

Contribution

First search for these specific electroweak penguin B decays with BaBar data, establishing upper limits on their branching fractions.

Findings

No significant signals observed for the decay modes.

Set 90% confidence level upper limits on branching fractions.

Provided constraints for future theoretical and experimental studies.

Abstract

Using a sample of 3.7 x 10^6$ Upsilon(4S) -> B Bbar 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-, B0 -> K*0 e+ e-, and B0 -> K*0 mu+ mu-. We observe no significant signals for these modes and set preliminary 90% C.L. upper limits of Br(B+ -> K+ e+ e-) < 12.5 x 10^(-6), Br(B+ -> K+ mu+ mu-) < 8.3 x 10^(-6), Br(B0 -> K*0 e+ e-) < 24.1 x 10^(-6), and Br(B0 -> K*0 mu+ mu-) < 24.5 x 10^(-6).