English

Angular Distributions in the Decays B -> K* l+l-

High Energy Physics - Experiment 2010-04-12 v2

Abstract

We use a sample of 384 million BBbar events collected with the Babar detector at the PEP-II e+e- collider to study angular distributions in the rare decays B -> K* l+l-, where l+l- is either e+e- or mu+mu-. For low dilepton invariant masses, m(l+l-)<2.5 GeV/c^2, we measure a lepton forward-backward asymmetry AFB=0.24 (+0.18,-0.23) +/- 0.05 and K* longitudinal polarization FL=0.35 +/- 0.16 +/- 0.04.Form(l+l)>3.2. For m(l+l-)>3.2 GeV/c^2, we measure AFB=0.76 (+0.52,-0.32) +/- 0.07 FL=0.71 (+0.20,-0.22) +/- 0.04.

Keywords

Cite

@article{arxiv.0804.4412,
  title  = {Angular Distributions in the Decays B -> K* l+l-},
  author = {The BABAR Collaboration and B. Aubert},
  journal= {arXiv preprint arXiv:0804.4412},
  year   = {2010}
}

Comments

7 pages, 4 postscript figures, submitted to Phys. Rev. Lett; v1 withdrawn from PRL; v2 8 pages, 4 postscript figures resubmitted to PRD-RC

R2 v1 2026-06-21T10:35:12.979Z