Abstract
Anomalous quartic couplings between the electroweak gauge bosons may contribute to the and final states produced in collisions. This analysis uses the LEP2 OPAL data sample at center-of-mass energies up to 209 GeV. Event selections identify and events in which the two photons are reconstructed within the detector acceptance. The cross section for the process is measured. Averaging over all energies, the ratio of the observed cross section to the standard model expectation is where the errors represent the statistical and systematic uncertainties respectively. The and data are used to constrain possible anomalous and couplings. Combining with previous OPAL results from the final state, the 95% confidence level limits on the anomalous coupling parameters and are found to be where is the energy scale of the new physics. Limits found when allowing two or more parameters to vary are also presented.
- Received 23 February 2004
DOI:https://doi.org/10.1103/PhysRevD.70.032005
©2004 American Physical Society