Production of chi(c2) mesons in photon-photon collisions at LEP

摘要

We present an observation at LEP of the production of chi(c2) mesons in the collisions of two quasi-real photons using the OPAL detector. The chi(c2) mesons are reconstructed in the decay channel chi(c2) --> J/psi gamma --> l(+) l(-) gamma (with l = e, mu) using all data taken at e(+)e(-) centre-of-mass energies of 91 and 183 GeV, corresponding to integrated luminosities of 167 and 55 pb(-1) respectively. The two-photon width of the chi(c2) is determined to be Gamma(chi(c2) --> gamma gamma) = 1.76 +/- 0.47 +/- 0.37 +/- 0.15 keV, where the first error is statistical, the second is systematic and the third comes from branching ratio uncertainties. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 27]