Next-to-next-to-leading-order logarithmic corrections at small transverse momentum in hadronic collisions

We study the region of small transverse momenta in q (q) over bar- and gg-initiated processes with no colored particle detected in the final state. We present the universal expression of the O(alpha (2)(s)) logarithmically enhanced contributions up to next-to-next-to-leading-order logarithmic accuracy. From there we extract the coefficients that allow the resummation of the large logarithmic contributions. We find that the coefficient known in the literature as B-(2) is process dependent, since it receives a hard contamination from the one-loop correction to the leading-order subprocess. We present the general result of B-(2) for both quark and gluon channels.