Angular and Isospin Asymmetries in the Decays B->K(*)l+l-

TL;DR

This paper reports measurements of angular and isospin asymmetries in B meson decays to K(*)l+l-, providing insights into flavor-changing neutral currents and testing the Standard Model predictions.

Contribution

First detailed measurements of AFB, FL, and isospin asymmetries in B->K(*)l+l- decays across different dilepton mass regions using a large data sample.

Findings

Measured AFB and FL asymmetries in two mass bins.

Observed isospin rate asymmetries consistent with Standard Model.

Provided data to constrain new physics models.

Abstract

We use a sample of 384 million BBbar decays collected with the Babar detector at the PEP-II asymmetric e+e- storage ring to study the flavor-changing neutral current decays B->K(*)l+l-, where l+l- is either e+e- or mu+mu-. We present measurements in two dilepton mass bins, one below the J/psi resonance and the other above, of the lepton forward-backward asymmetry AFB and the longitudinal K* polarization FL in B->K*l+l-, along with isospin rate asymmetries in B->K*l+l- and B->Kl+l- final states.