# Measurement of Radiative Bhabha and Quasi-Real Compton Scattering

1 LAPP - Laboratoire d-Annecy-le-Vieux de Physique des Particules 2 IPNL - Institut de Physique Nucléaire de Lyon 3 CMS IPNL - Institut de Physique Nucléaire de Lyon

Abstract : We report on a study of radiative Bhabha and quasi-real Compton scattering at centre-of-mass energies between 50~{\GeV} and 170~{\GeV} and 20~{\GeV} and 140~{\GeV}, respectively, using the L3 detector at LEP. The analysis is based on data corresponding to an integrated luminosity of $232.2 \,\pb$. A total of 2856 radiative Bhabha and 4641 Compton scattering events are collected. Total and differential cross sections for both reactions are presented and found to be in good agreement with QED expectations. Our measurement of Compton scattering at the highest energies obtained so far is used to derive exclusion limits on the coupling $\lambda$ for the on-shell production of an excited electron $\e^{\star}$ decaying into a $\gamma\e$ pair in the mass range $20 \gev m {\e^{\star}} 170 \gev$.

Author: M. Acciarri O. Adriani M. Aguilar-Benitez S. Ahlen J. Alcaraz G. Alemanni A. Aloisio M G. Alviggi G. Ambrosi H. Anderhub V P. And

Source: https://hal.archives-ouvertes.fr/