Study of the e+e- -> Z gamma gamma -> q q~ gamma gamma Process at LEP

TL;DR

This paper analyzes the e+e- -> Z gamma gamma process at LEP energies, measuring cross sections and constraining quartic gauge couplings, confirming consistency with the Standard Model.

Contribution

It provides the first measurement of the e+e- -> Z gamma gamma process at LEP and sets limits on anomalous quartic gauge couplings.

Findings

Measured cross sections align with Standard Model predictions.

Constrained quartic gauge couplings within specified bounds.

Enhanced understanding of gauge boson interactions at high energies.

Abstract

The process e^+e^- -> Z gamma gamma -> q q~ gamma gamma is studied in 0.5 fb-1 of data collected with the L3 detector at centre-of-mass energies between 130.1 GeV and 201.7 GeV. Cross sections are measured and found to be consistent with the Standard Model expectations. The study of the least energetic photon constrains the quartic gauge boson couplings to -0.008 GeV-2 < a_0/\Lambda^2 < 0.005 GeV-2 and -0.007 GeV-2 < a_c/\Lambda^2 < 0.011 GeV-2, at 95% confidence level.