  In high-energy processes which are sensitive to small transverse momenta,
individual contributions from collinear and soft momentum regions are not
separately well-defined in dimensional regularization. A simple possibility to
solve this problem is to introduce additional analytic regulators. We point out
that in massless theories the unregularized singularities only appear in
real-emission diagrams and that the additional regulators can be introduced in
such a way that gauge invariance and the factorized eikonal structure of soft
and collinear emissions is maintained. This simplifies factorization proofs and
implies, at least in the massless case, that the structure of Soft-Collinear
Effective Theory remains completely unchanged by the presence of the additional
regulators. Our formalism also provides a simple operator definition of
transverse parton distribution functions.
