Testing the equivalent photon approximation of the proton in the process \(ep \rightarrow \nu W X\)

The accuracy of the equivalent photon approximation of the proton in describing the inelastic process \(ep \rightarrow \nu W X\) is investigated. In particular, the scale dependence of the corresponding inelastic photon distribution is discussed. Furthermore, an estimate of the total number of events, including the ones coming from the elastic and quasi-elastic channels of the reaction, is given for the HERA collider.