Evidence for the Rare DecayB→K*ℓ+ℓ−and Measurement of theB→Kℓ+ℓ−Branching Fraction

2003/08/16 by B. Aubert, R. Barate, D. Boutigny +97 · 7 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex

paper · pdf · doi:10.1103/physrevlett.91.221802

published as Phys.Rev.Lett.91:221802,2003 · 7 pages, 2 postscript figues, submitted to Phys. Rev. Lett

arxiv created 2003/08/16 · openalex publication_date 2003/11/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04

Abstract

We present evidence for the flavor-changing neutral current decay B\ensuremath→K^*\ensuremathℓ⁺\ensuremathℓ^\ensuremath- and a measurement of the branching fraction for the related process B\ensuremath→K\ensuremathℓ⁺\ensuremathℓ^\ensuremath-, where \ensuremathℓ⁺\ensuremathℓ^\ensuremath- is either an e⁺e^\ensuremath- or a \ensuremathμ⁺\ensuremathμ^\ensuremath- pair. These decays are highly suppressed in the standard model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises 123\ifmmode×\else\texttimes\fi10⁶ \ensuremathΥ(4S)\ensuremath→BB decays collected with the BABAR detector at the SLAC PEP-II e⁺e^\ensuremath- storage ring. Averaging over K^(*) isospin and lepton flavor, we obtain the branching fractions B(B\ensuremath→K\ensuremathℓ⁺\ensuremathℓ^\ensuremath-)=(0.65_\ensuremath-0.13^+0.14\ifmmode±\else\textpm\fi0.04)\ifmmode×\else\texttimes\fi10^\ensuremath-6 and B(B\ensuremath→K^*\ensuremathℓ⁺\ensuremathℓ^\ensuremath-)=(0.88_\ensuremath-0.29^+0.33\ifmmode±\else\textpm\fi0.10)\ifmmode×\else\texttimes\fi10^\ensuremath-6, where the uncertainties are statistical and systematic, respectively. The significance of the B\ensuremath→K\ensuremathℓ⁺\ensuremathℓ^\ensuremath- signal is over 8\ensuremathσ, while for B\ensuremath→K^*\ensuremathℓ⁺\ensuremathℓ^\ensuremath- it is 3.3\ensuremathσ.

Citations

• Search for the Rare DecaysB→Kl+l−andB→K*l+l−
• Review of particle properties
• Observation of the decay B --> Kl+l-.

Cited by

• Analysis of rareB→K0*(1430)ℓ+ℓ−decay within QCD sum rules
• Large forward-backward asymmetry inB→Kμ+μ−from new physics tensor operators
• Double-lepton polarizations inB→ℓ+ℓ−γdecay
• PROBE THE EFFECTS OF SPLIT SUSY IN RARE B DECAYS
• NEW PHYSICS UPPER BOUND ON THE BRANCHING RATIO OF Bs → l+l-γ
• Factorization inB→Kπℓ+ℓ−decays
• Forward-backward asymmetry, branching ratio and rate difference between electron and muon channels of B → K 1(K*)ℓ+ℓ− transition in supersymmetric models