Next-to-next-to-leading logarithmic corrections at small transverse   momentum in hadronic collisions
  We study the region of small transverse momenta in qqbar- and gg-initiated processes with no colored particle detected in the final state. We present the universal expression of the O(alpha_s^2) logarithmically enhanced contributions up to next-to-next-to-leading 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. In particular, in the case of Higgs production, this result will be relevant to improve the matching between resummed predictions and fixed order calculations. 
D. de Florian and M. Grazzini (ETH-Zurich)