f1 (1285) formation in two-photon collisions at LEP

The etapi(+)pi(-) final state in two-photon collisions is studied with the L3 detector at LEP, at centre-of-mass energies from 183 to 209 GeV with an integrated luminosity of 664.6 pb(-1). The f(1) (1285) meson is observed and the Q(2) dependence of its production is compared to different form factor models. The gammagamma-coupling parameter Gamma(gammagamma) is found to be 3.5 +/- 0.6(stat.) +/- 0.5 (sys.) keV. The branching fraction Gamma(f(1)(1285) --> a(0)pi) / Gamma(f(1)(1285) --> etapipi) is also measured. (C) 2002 Elsevier Science B.V. All rights reserved.