  We consider the resummation of the logarithmic contributions to the region of
small transverse momenta in the distributions of high-mass systems (lepton
pairs, vector bosons, Higgs particles, ....) produced in hadron collisions. We
point out that the resummation formulae that are usually used to compute the
distributions in perturbative QCD involve process-dependent form factors and
coefficient functions. We present a new universal form of the resummed
distribution, in which the dependence on the process is embodied in a single
perturbative factor. The new form simplifies the calculation of non-leading
logarithms at higher perturbative orders. It can also be useful to
systematically implement process-independent non-perturbative effects in
transverse-momentum distributions. We also comment on the dependence of these
distributions on the factorization and renormalization scales.
