Electroweak radiative corrections to the three channels of the process f1(f1)over-barZA→0

We have calculated the electroweak radiative corrections at the O(alpha) level to the three channels of the process f(1)(f(1)) over bar ZA -> 0 nd implemented them into the SANC system. Here A stands for the photon and f(1) for a first generation fermion whose mass is neglected everywhere except in the arguments of logarithmic functions. The symbol -> 0 means that 4-momenta of all the external particles flow inwards. We present the complete analytical results for the covariant and helicity amplitudes for three cross channels: f(1)(f(1)) over bar -> Z gamma, Z -> f(1)(f(1)over bar>) over bar )over bar>gamma and f(1)gamma -> f(1)Z. The one-loop scalar form factors of these channels are simply related by an appropriate permutation of their arguments, s,t,u. To check the correctness of our results we first of all observe the independence of the scalar form factors on the gauge parameters and the validity of the Ward identity, i.e. external photon transversality, and, secondly, compare our numerical results with the other independent calculations available to us.