Factorization theorem for photons and gluons in hard processes Original Research Article

Factorization of photons and gluons in high energy scattering amplitudes is discussed. In contrast to Lowʹs theorem for the factorization condition where vanishingly small momenta for emitted photons were required, we discuss bremsstrahlung with non-vanishing momenta. We show, using dispersion relations, that with all the higher-loop radiative corrections taken into account in the leading logarithmic approximation, a new kind of factorization, with the only requirement of minimally small transverse momenta, arises. This provides an extension of the factorization domain, first proposed in Gribovʹs theorem for photon bremsstrahlung in the framework of phenomenological description of high energy hadron-hadron reactions.