Wgamma production and limits on anomalous WWgamma couplings in ppbar collisions

We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W -> lnu+gamma production in egamma and mugamma final states. Using data corresponding to an integrated luminosity of 4.2 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider, the cross section multiplied by the branching fraction for the process ppbar -> Wgamma+X -> lnugamma+X, measured to be 15.8 +/- 0.8 (stat.) +/- 1.2 (syst.) pb, and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WWgamma couplings for data from hadron colliders: -0.4 < Delta kappa_gamma < 0.4 and -0.08 < lambda_gamma < 0.07 at the 95% C.L.