Limits on Anomalous $WWγ$ Couplings from $p\bar{p} \to W γ+ X$ Events at $\sqrt{s}=1.8$ TeV

Abstract

We have measured the $WWγ$ gauge boson coupling parameters using $p\bar{p}\to \ellνγ+X$ ($\ell=e,μ$) events at $\sqrt{s}=1.8$ TeV. The data, corresponding to an integrated luminosity of 89.1 pb^{-1}, were collected using the D0 detector at the Fermilab Tevatron Collider. The measured cross section times branching ratio for $p\bar{p} \to Wγ+X$ with $p_T^γ$ > 10 GeV/c and $R_{\ellγ} > 0.7$ is ${11.8}^{+1.7}_{-1.6} \pm 2.0$ pb, in agreement with the Standard Model prediction. The one degree of freedom 95% confidence level limits on individual CP-conserving parameters are $-0.98<Δκ<1.01$ and $-0.33<λ<0.31$. Similar limits are set on the CP}violating coupling parameters.