Eur. Phys. J. C 25, 421-425 (2002)
Two photon width ofN. Fabiano1 and G. Pancheri2
1 Perugia University and INFN, via Pascoli 06100, Perugia, Italy
2 INFN National Laboratories, P.O. Box 13, 00044, Frascati, Italy
(Received: 25 October 2001 / Revised version: 7 March 2002 Published online: 30 August 2002 )
We discuss the measured partial width of the pseudoscalar charmonium state into two photons. Predictions from potential models are examined and compared with experimental values. On including radiative corrections, it is found that present measurements are compatible both with a QCD type potential and with a static Coulomb potential. The latter is then used to give an estimate on the decay into two photons. Results for are also compared with those from data through the NRQCD model.
© Società Italiana di Fisica, Springer-Verlag 2002