Test of Lepton Universality in {Upsilon}(1S) Decays at BABAR

Journal Article · Fri May 14 00:00:00 EDT 2010 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.104.191801· OSTI ID:21410721

Amo Sanchez, P del; Lees, J P; Poireau, V; Prencipe, E; Tisserand, V ^[1]; Garra Tico, J; Grauges, E ^[2]; Martinelli, M; Palano, A; Pappagallo, M ^[3]; Eigen, G; Stugu, B; Sun, L ^[4]; Battaglia, M; Brown, D N; Hooberman, B; Kerth, L T; Kolomensky, Yu G; Lynch, G; Osipenkov, I L ^[5]

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1. Laboratoire d'Annecy-le-Vieux de Physique des Particules (LAPP), Universite de Savoie, CNRS/IN2P3, F-74941 Annecy-Le-Vieux (France)
2. Universitat de Barcelona, Facultat de Fisica, Departament ECM, E-08028 Barcelona (Spain)
3. INFN Sezione di Bari, I-70126 Bari (Italy)
4. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)
5. Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States)

The ratio R{sub {tau}{mu}({Upsilon}(1S))}={Gamma}{sub {Upsilon}(1S){yields}{tau}}{sup +}{sub {tau}}{sup -}/{Gamma}{sub {Upsilon}(1S){yields}{mu}}{sup +}{sub {mu}}{sup -} is measured using a sample of (121.8{+-}1.2)x10{sup 6{Upsilon}}(3S) events recorded by the BABAR detector. This measurement is intended as a test of lepton universality and as a search for a possible light pseudoscalar Higgs boson. In the standard model (SM) this ratio is expected to be close to 1. Any significant deviations would violate lepton universality and could be introduced by the coupling to a light pseudoscalar Higgs boson. The analysis studies the decays {Upsilon}(3S){yields}{Upsilon}(1S){pi}{sup +{pi}-}, {Upsilon}(1S){yields}l{sup +}l{sup -}, where l={mu}, {tau}. The result, R{sub {tau}{mu}({Upsilon}(1S))}=1.005{+-}0.013(stat){+-}0.022(syst), shows no deviation from the expected SM value, while improving the precision with respect to previous measurements.

• OSTI ID: 21410721
• Journal Information: Physical Review Letters, Vol. 104, Issue 19; Other Information: DOI: 10.1103/PhysRevLett.104.191801; (c) 2010 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCURACY
HIGGS BOSONS
LEPTONS
PARTICLE DECAY
PARTICLE DISCRIMINATION
PIONS MINUS
PIONS PLUS
STANDARD MODEL
BOSONS
DECAY
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
GRAND UNIFIED THEORY
HADRONS
MATHEMATICAL MODELS
MESONS
PARTICLE IDENTIFICATION
PARTICLE MODELS
PIONS
POSTULATED PARTICLES
PSEUDOSCALAR MESONS
QUANTUM FIELD THEORY
UNIFIED GAUGE MODELS