Measurements of branching fractions, rate asymmetries, and angular distributions in the rare decays B{yields}Kl{sup +}l{sup -} and B{yields}K*l{sup +}l{sup -}

Journal Article · Mon May 01 00:00:00 EDT 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.73.092001· OSTI ID:20782963

Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A ^[1]; Grauges, E ^[2]; Palano, A; Pappagallo, M ^[3]; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S ^[4]; Eigen, G; Ofte, I ^[5]

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1. Laboratoire de Physique des Particules, F-74941 Annecy-le-Vieux (France)
2. Universitat de Barcelona, Facultat de Fisica Dept. ECM, E-08028 Barcelona (Spain)
3. Universita di Bari, Dipartimento di Fisica and INFN, I-70126 Bari (Italy)
4. Institute of High Energy Physics, Beijing 100039 (China)
5. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)

We present measurements of the flavor-changing neutral current decays B{yields}Kl{sup +}l{sup -} and B{yields}K*l{sup +}l{sup -}, where l{sup +}l{sup -} is either an e{sup +}e{sup -} or {mu}{sup +}{mu}{sup -} pair. The data sample comprises 229x10{sup 6} {upsilon}(4S){yields}BB decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} 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{yields}Kl{sup +}l{sup -})=(0.34{+-}0.07{+-}0.02)x10{sup -6}, B(B{yields}K*l{sup +}l{sup -})=(0.78{sub -0.17}{sup +0.19}{+-}0.11)x10{sup -6}, the direct CP asymmetries of these decays, and the relative abundances of decays to electrons and muons. For two regions in l{sup +}l{sup -} mass, above and below m{sub J/{psi}}, 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{yields}K*l{sup +}l{sup -} decays. Upper limits are obtained for the lepton-flavor-violating decays B{yields}Ke{mu} and B{yields}K*e{mu}. All measurements are consistent with standard model expectations.

• OSTI ID: 20782963
• Journal Information: Physical Review. D, Particles Fields, Vol. 73, Issue 9; Other Information: DOI: 10.1103/PhysRevD.73.092001; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR DISTRIBUTION
ASYMMETRY
B MESONS
BRANCHING RATIO
CP INVARIANCE
ELECTRON PAIRS
ELECTRONS
FLAVOR MODEL
K*-892 MESONS
KAONS
MULTIPARTICLE SPECTROMETERS
MUONS MINUS
MUONS PLUS
NEUTRAL CURRENTS
PARTICLE PRODUCTION
PEP STORAGE RINGS
POLARIZATION
POSITRONS
REST MASS
SEMILEPTONIC DECAY
STANDARD MODEL
UPSILON-10580 MESONS