Title:
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Observation of the χc2(2P) meson in the reaction γγ→D¯¯¯D at BABAR
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Author:
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Garra Ticó, Jordi; Graugés Pous, Eugeni; BABAR Collaboration
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Other authors:
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Universitat de Barcelona |
Abstract:
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A search for the Z ( 3930 ) resonance in γ γ production of the D ¯¯¯ D system has been performed using a data sample corresponding to an integrated luminosity of 384 fb − 1 recorded by the BABAR experiment at the PEP-II asymmetric-energy electron-positron collider. The D ¯¯¯ D invariant mass distribution shows clear evidence of the Z ( 3930 ) state with a significance of 5.8 σ . We determine mass and width values of ( 3926.7 ± 2.7 ± 1.1 ) MeV / c 2 and ( 21.3 ± 6.8 ± 3.6 ) MeV , respectively. A decay angular analysis provides evidence that the Z ( 3930 ) is a tensor state with positive parity and C parity ( J P C = 2 ++ ); therefore we identify the Z ( 3930 ) state as the χ c 2 ( 2 P ) meson. The value of the partial width Γ γ γ × B ( Z ( 3930 ) → D ¯¯¯ D ) is found to be ( 0.24 ± 0.05 ± 0.04 ) keV . |
Subject(s):
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-Física de partícules -Experiments -Particle physics -Experiments |
Rights:
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(c) American Physical Society, 2010
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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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