Measurements of branching fractions, rate asymmetries, and angular distributions in the rare decaysB→Kℓ+ℓ−andB→K*ℓ+ℓ−

2006/04/30 by The BABAR Collaboration, B. Aubert, R. Barate +98
Chemistry · Physics and Astronomy · #Analytical Chemistry (journal) #Asymmetry #Branching fraction #Chemistry #Electron #Electron–positron annihilation #Electroweak interaction #Electroweak scale #Hadron #Lepton #Muon #Neutrino Physics Research #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics beyond the Standard Model #Quantum Chromodynamics and Particle Interactions #hep-ex

paper · pdf · doi:10.1103/physrevd.73.092001

published as Phys.Rev.D73:092001,2006 · 19 pages, 14 figures, 5 tables. References added. Accepted by Phys. Rev. D

openalex publication_date 2006/05/05 · arxiv created 2006/05/07 · arxiv updated 2010/03/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06

Abstract

We present measurements of the flavor-changing neutral current decays B\ensuremath→K\ensuremathℓ⁺\ensuremathℓ^\ensuremath- and B\ensuremath→K^*\ensuremathℓ⁺\ensuremathℓ^\ensuremath-, where \ensuremathℓ⁺\ensuremathℓ^\ensuremath- is either an e⁺e^\ensuremath- or \ensuremathμ⁺\ensuremathμ^\ensuremath- pair. The data sample comprises 229\ifmmode×\else\texttimes\fi10⁶ \ensuremathΥ(4S)\ensuremath→BB decays collected with the BABAR detector at the PEP-II e⁺e^\ensuremath- storage ring. Flavor-changing neutral current decays are highly suppressed in the standard model and their predicted properties could be significantly modified by new physics at the electroweak scale. We measure the branching fractions B(B\ensuremath→K\ensuremathℓ⁺\ensuremathℓ^\ensuremath-)=(0.34\ifmmode±\else\textpm\fi0.07\ifmmode±\else\textpm\fi0.02)\ifmmode×\else\texttimes\fi10^\ensuremath-6, B(B\ensuremath→K^*\ensuremathℓ⁺\ensuremathℓ^\ensuremath-)=(0.78_\ensuremath-0.17^+0.19\ifmmode±\else\textpm\fi0.11)\ifmmode×\else\texttimes\fi10^\ensuremath-6, the direct CP asymmetries of these decays, and the relative abundances of decays to electrons and muons. For two regions in \ensuremathℓ⁺\ensuremathℓ^\ensuremath- mass, above and below m_J/\ensuremathψ, we measure partial branching fractions and the forward-backward angular asymmetry of the lepton pair. In these same regions we also measure the K^* longitudinal polarization in B\ensuremath→K^*\ensuremathℓ⁺\ensuremathℓ^\ensuremath- decays. Upper limits are obtained for the lepton-flavor-violating decays B\ensuremath→Ke\ensuremathμ and B\ensuremath→K^*e\ensuremathμ. All measurements are consistent with standard model expectations.

Citations

• Forward-backward asymmetry ofB→(π,K)l+l−:Supersymmetry at work
• Bd,s→ρ,ω,K*,ϕdecay form factors from light-cone sum rules reexamined
• THE USE OF MULTIPLE MEASUREMENTS IN TAXONOMIC PROBLEMS
• RareB→K*l+l−decay in light cone QCD
• Evidence for the Rare DecayB→K*ℓ+ℓ−and Measurement of theB→Kℓ+ℓ−Branching Fraction
• Improved model-independent analysis of semileptonic and radiative rareBdecays
• Model independent constraints on leptoquarks from rare processes
• Search for the Rare DecaysB→Kl+l−andB→K*l+l−
• Exclusive semileptonic rare decaysB→(K,K*)l+l−in supersymmetric theories
• Observation ofB→K*ℓ+ℓ−
• The BABAR detector
• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• More model-independent analysis ofb→sprocesses