Bremsstrahlung Model and Scaling in Electroproduction: A Second Look

Deep-inelastic electron-proton scattering is investigated in the bremsstrahlung model. In this model a high-energy nucleon emits massive neutral vector mesons when it interacts with the electron. In the electron rest frame where the proton momentum tends to infinity, the mesons are considered soft and an eikonal approximation is made for the nucleon propagator. This leads to a coordinate-space description similar to the elastic-scattering case. The leading light-cone singularity emerging from this description is precisely of the type assumed for Bjorken scaling and arises from the propagation of the final proton. The kinematic region found relevant corresponds to $q_{\perp }$ finite and $s_{\mathrm{ep}}\simeq 2P·q$. Radiative corrections due to soft mesons when included preserve scaling. None of these results were obtained in previous studies of the bremsstrahlung model using different calculational techniques.