COMPLETE O(ALPHA) QED CORRECTIONS TO THE PROCESS EP-]EX IN MIXED VARIABLES

The complete set of O(alpha) QED corrections with soft photon exponent iation to the process ep --> eX in mixed variables (y = Y-h, Q(2) = Q( 1);(2) calculated in the quark-parton model, including the lepton-quar k interference and the quarkonic corrections which were unknown so far . The interference corrections amount to a few percent or less and bec ome negligible at small x. The leading logarithmic terms proportional to 1n(Q(2)/m(q)(2)) from radiation off quarks are discussed and the no n-logarithmic quarkonic corrections are found to be negligible for alm ost all experimentally accessible x and y.