Resonance production in two photon collisions at LEP with the L3 detector

The ee to eeK/sub S//sup 0/K/sup +or-/ pi /sup -or+/, ee to ee eta pi /sup +/ pi /sup -/ and e/sup +/e/sup to /e/sup +/e/sup -/ pi /sup +/ pi /sup -/ pi /sup +/ pi /sup -/ final states are studied with the L3 detector at LEP using data collected at center-of-mass energies from 160 GeV up to 202 GeV. The mass spectrum of the K/sub S//sup 0/K/sup +or-/ pi /sup -or+/ final state shows an enhancement around 1470 MeV, which is identified with the pseudoscalar meson eta (1440). This state is observed in gamma gamma collisions for the first time and its two photon width is measured. Clear evidence is also obtained for the formation of the axial vector mesons f/sub 1/(1420) and f/sub 1 /(1285). In the eta pi /sup +/ pi /sup -/ channel the f/sub 1/(1285) is observed and upper limits for the formation of eta (1440) and eta (1295) are obtained. The process e/sup +/e/sup to /e/sup +/e/sup -/ pi /sup +/ pi /sup -/ pi /sup +/ pi /sup -/ is dominated by rho /sup 0/ rho /sup 0/ production. A spin parity analysis of the rho /sup 0/ rho /sup 0/ system for W/sub gamma gamma /<3 GeV shows a dominance of J/sup P/=2/sup +/ and helicity 2. A contribution of J/sup P/=0/sup +/ is also observed whereas contributions of negative parity states and (J/sup P/, J/sub z/)=(2/sup +/,0) are found to be negligible. For the gamma gamma mass region W/sub gamma gamma />3 GeV the f/sub 2/(1270) meson is observed. (27 refs).