${\cal O}(α^2 L^2)$ radiative corrections to deep inelastic $ep$ scattering for different kinematical variables

The QED radiative corrections are calculated in the leading log approximation up to ${\cal O}(\alpha^2)$ for different definitions of the kinematical variables using jet measurement, the 'mixed' variables, the double angle method, and a measurement based on $\theta_e$ and $y_{JB}$. Higher order contributions due to exponentiation of soft radiation are included.