Precision tests of the J/ψ from full lattice QCD: mass, leptonic width, and radiative decay rate to η_{c}

Donald, G.C., Davies, C.T.H. , Dowdall, R.J., Follana, E., Hornbostel, K., Koponen, J., Lepage, G.P. and McNeile, C. (2012) Precision tests of the J/ψ from full lattice QCD: mass, leptonic width, and radiative decay rate to η_{c}. Physical Review D, 86(9), 094501. (doi: 10.1103/PhysRevD.86.094501)

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Abstract

We calculate the J/ψ mass, leptonic width and radiative decay rate to γηc from lattice QCD including u, d and s quarks in the sea for the first time. We use the highly improved staggered quark formalism and nonperturbatively normalized vector currents for the leptonic and radiative decay rates. Our results are: MJ/ψ-Mηc=116.5(3.2)  MeV; Γ(J/ψ→e+e-)=5.48(16)  keV; Γ(J/ψ→γηc)=2.49(19)  keV. The first two are in good agreement with experiment, with Γ(J/ψ→e+e-) providing a test of a decay matrix element in QCD, independent of Cabibbo-Kobayashi-Maskawa uncertainties, to 2%. At the same time results for the time moments of the correlation function can be compared to values from the charm contribution to σ(e+e-→hadrons), giving a 1.5% test of QCD. Our results show that an improved experimental error would enable a similarly strong test from Γ(J/ψ→γηc).

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Dowdall, Dr Rachel and Koponen, Dr Jonna and Davies, Professor Christine
Authors: Donald, G.C., Davies, C.T.H., Dowdall, R.J., Follana, E., Hornbostel, K., Koponen, J., Lepage, G.P., and McNeile, C.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Physical Review D
Publisher:American Physical Society
ISSN:1550-7998
Published Online:02 November 2012
Copyright Holders:Copyright © 2012 American Physical Society
First Published:First published in Physical Review D 86(9):094501
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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