Improved description of Bose-Einstein Correlation function

The L3 data on Bose-Einstein correlations of equally charged pion pairs produced in hadronic Z decays are analyzed in terms of various parametrizations. Preliminary results are presented here.Comment: Presented at the RHIC School 04, 4th Budapest Winter School on Heavy Ion Physics, Budapest, Hungary, December 1-3, 2004. To be published in Acta Physica Hungarica Heavy Ion Physic

Compton scattering of quasi-real virtual photons at LEP

Compton scattering of quasi-real virtual photons, γe± → γe±, is studied with 0.6 fb−1 of data collected by the L3 detector at the LEP e+e− collider at centre-of-mass energies √s = 189–209 GeV. About 4500 events produced by the interaction of virtual photons emitted by e± of one beam with e∓ of the opposite beam are collected for effective centre-of-mass energies of the photon–electron and photon–positron systems in the range from √s' = 35 GeV up to √s' = 175 GeV, the highest energy at which Compton scattering was ever probed. The cross sections of the γe± → γe± process as a function of √s' and of the rest-frame scattering angle are measured, combined with previous L3 measurements down to √s'≃20 GeV, and found to agree with the QED expectations.Facultad de Ciencias Exacta