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Title: 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 -}

Abstract

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.

Authors:
; ; ; ; ; ; ; ; ;  [1];  [2]; ;  [3]; ; ; ; ;  [4]; ;  [5]
  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) (and others)
Publication Date:
OSTI Identifier:
20782963
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.73.092001; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Aubert, B., Barate, R., Bona, M., Boutigny, D., Couderc, F., Karyotakis, Y., Lees, J.P., Poireau, V., Tisserand, V., Zghiche, A., Grauges, E., Palano, A., Pappagallo, M., Chen, J.C., Qi, N.D., Rong, G., Wang, P., Zhu, Y.S., Eigen, G., and Ofte, I. 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 -}. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.092001.
Aubert, B., Barate, R., Bona, M., Boutigny, D., Couderc, F., Karyotakis, Y., Lees, J.P., Poireau, V., Tisserand, V., Zghiche, A., Grauges, E., Palano, A., Pappagallo, M., Chen, J.C., Qi, N.D., Rong, G., Wang, P., Zhu, Y.S., Eigen, G., & Ofte, I. 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 -}. United States. doi:10.1103/PHYSREVD.73.092001.
Aubert, B., Barate, R., Bona, M., Boutigny, D., Couderc, F., Karyotakis, Y., Lees, J.P., Poireau, V., Tisserand, V., Zghiche, A., Grauges, E., Palano, A., Pappagallo, M., Chen, J.C., Qi, N.D., Rong, G., Wang, P., Zhu, Y.S., Eigen, G., and Ofte, I. Mon . "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 -}". United States. doi:10.1103/PHYSREVD.73.092001.
@article{osti_20782963,
title = {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 -}},
author = {Aubert, B. and Barate, R. and Bona, M. and Boutigny, D. and Couderc, F. and Karyotakis, Y. and Lees, J.P. and Poireau, V. and Tisserand, V. and Zghiche, A. and Grauges, E. and Palano, A. and Pappagallo, M. and Chen, J.C. and Qi, N.D. and Rong, G. and Wang, P. and Zhu, Y.S. and Eigen, G. and Ofte, I.},
abstractNote = {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.},
doi = {10.1103/PHYSREVD.73.092001},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 73,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2006},
month = {Mon May 01 00:00:00 EDT 2006}
}
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  • We present measurements of the branching fractions, longitudinal polarization, and direct CP-violation asymmetries for the decays B{sup +}{yields}{rho}{sup 0}K*{sup +} and B{sup +}{yields}f{sub 0}(980)K*{sup +} with a sample of (467{+-}5)x10{sup 6}BB pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. We observe B{sup +}{yields}{rho}{sup 0}K{sup *+} with a significance of 5.3{sigma} and measure the branching fraction B(B{sup +}{yields}{rho}{sup 0}K{sup *+})=(4.6{+-}1.0{+-}0.4)x10{sup -6}, the longitudinal polarization f{sub L}=0.78{+-}0.12{+-}0.03, and the CP-violation asymmetry A{sub CP}=0.31{+-}0.13{+-}0.03. We observe B{sup +}{yields}f{sub 0}(980)K*{sup +} and measure the branching fraction B(B{sup +}{yields}f{sub 0}(980)K*{sup +})xB(f{sub 0}(980){yields}{pi}{sup +}{pi}{supmore » -})=(4.2{+-}0.6{+-}0.3)x10{sup -6} and the CP-violation asymmetry A{sub CP}=-0.15{+-}0.12{+-}0.03. The first uncertainty quoted is statistical and the second is systematic.« less
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