Title:
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Observation of Υ(4S) Decays to π+π−Υ(1S) and π+π−Υ(2S)
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Author:
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Graugés Pous, Eugeni; BABAR Collaboration
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Other authors:
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Universitat de Barcelona |
Abstract:
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We present the first measurement of Υ ( 4 S ) decays to π + π − Υ ( 1 S ) and π + π − Υ ( 2 S ) based on a sample of 230 × 10 6 Υ ( 4 S ) mesons collected with the BABAR detector. We measure the product branching fractions B ( Υ ( 4 S ) → π + π − Υ ( 1 S ) ) × B ( Υ ( 1 S ) → μ + μ − ) = ( 2.23 ± 0.25 stat ± 0.27 syst ) × 10 − 6 and B ( Υ ( 4 S ) → π + π − Υ ( 2 S ) ) × B ( Υ ( 2 S ) → μ + μ − ) = ( 1.69 ± 0.26 stat ± 0.20 syst ) × 10 − 6 , from which we derive the partial widths Γ ( Υ ( 4 S ) → π + π − Υ ( 1 S ) ) = ( 1.8 ± 0.4 ) keV and Γ ( Υ ( 4 S ) → π + π − Υ ( 2 S ) ) = ( 2.7 ± 0.8 ) keV . |
Subject(s):
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-Física de partícules -Experiments -Particle physics -Experiments |
Rights:
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(c) American Physical Society, 2006
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Document type:
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Article Article - Published version |
Published by:
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American Physical Society
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