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Two photon width of eta_c

Nicola Fabiano·Giulia Pancheri
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Abstract

We discuss the measured partial width of the pseudoscalar charmonium state, $η_c$, into two photons. Predictions from potential models are examined and compared with experimental values. Including radiative corrections, it is found that present measurements are compatible both with a QCD type potential and with a static Coulomb potential, with $α_s$ evaluated at two loops. Results are also compared with those from $\jpsi$ data through the NRQCD model.

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Nicola Fabiano, Giulia Pancheri. 2001-10-16. Two photon width of eta_c. https://doi.org/10.1142/9789812777157_0059

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