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

TL;DR

This study measures the $WW\gamma$ gauge boson couplings at the Tevatron collider, setting limits on anomalous couplings and confirming consistency with the Standard Model through analysis of $par{p} o W\gamma + X$ events.

Contribution

First measurement of $WW\gamma$ couplings at Tevatron, providing new limits on anomalous couplings and testing Standard Model predictions.

Findings

Measured cross section consistent with Standard Model

Set 95% CL limits on anomalous couplings

Confirmed no significant deviation from Standard Model

Abstract

We have measured the $WW\gamma$ gauge boson coupling parameters using $p\bar{p}\to \ell\nu\gamma+X$ ($\ell=e,\mu$) 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 $p\bar{p} \to W\gamma+X$ with $p_T^\gamma$ > 10 GeV/c and $R_{\ell\gamma} > 0.7$ 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 $-0.98<\Delta\kappa<1.01$ and $-0.33<\lambda<0.31$. Similar limits are set on the CP}violating coupling parameters.