We have measured the total and differential cross sections of the reaction e+ e- --> gamma-gamma(gamma) at center-of-mass energies around 91 GeV, with an integrated luminosity of 14.2 pb-1. The results are in good agreement with QED predictions. We set lower limits, at 95% confidence level, on the QED cutoff parameters of LAMBDA+ > 139 GeV, LAMBDA- > 108 GeV and on the mass of an excited electron of m(e*) > 127 GeV. We searched for Z0 rare decays with photonic signatures in the final state. Upper limits, at 95% confidence level, for the branching ratio of ZO decaying into pi-0-gamma/gamma-gamma, eta-gamma and gamma-gamma-gamma are 1.2 x 10(-4), 1.8 x 10(-4), 3.3 x 10(-5) respectively.
A Test of Quantum Electrodynamics In the Reaction E+e- -]gamma-gamma(gamma)
SANTOCCHIA, Attilio;FIANDRINI, Emanuele;BERTUCCI, Bruna;PAULUZZI, Michele
1992
Abstract
We have measured the total and differential cross sections of the reaction e+ e- --> gamma-gamma(gamma) at center-of-mass energies around 91 GeV, with an integrated luminosity of 14.2 pb-1. The results are in good agreement with QED predictions. We set lower limits, at 95% confidence level, on the QED cutoff parameters of LAMBDA+ > 139 GeV, LAMBDA- > 108 GeV and on the mass of an excited electron of m(e*) > 127 GeV. We searched for Z0 rare decays with photonic signatures in the final state. Upper limits, at 95% confidence level, for the branching ratio of ZO decaying into pi-0-gamma/gamma-gamma, eta-gamma and gamma-gamma-gamma are 1.2 x 10(-4), 1.8 x 10(-4), 3.3 x 10(-5) respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
