ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract. The process ${\rm e^+e^-}\to \gamma \gamma (\gamma)$ is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb $^{-1}$ taken at centre-of-mass energies of 130–172 GeV. The measured cross-sections agree well with the expectation from QED. In a combined fit using data from all centre-of-mass energies, the angular distribution is used to obtain improved limits on the cut-off parameters: $\Lambda_+ 〉 195$ GeV and $\Lambda_- 〉 210$ GeV (95% CL). In addition, limits on non-standard ${\rm e^+e^-}\gamma$ couplings and contact interactions, as well as a 95% CL mass limit for an excited electron, $M_{\mathrm{e^{\ast}}} 〉 194$ GeV for an ${\rm e^+e^-}\gamma$ coupling $\kappa = 1$ , are determined.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01245795
