All-order colour structure and two-loop anomalous dimension of soft radiation in heavy-particle pair production at the LHC

We consider the factorization and resummation of soft and Coulomb gluons for pair-production processes of heavy coloured particles at hadron colliders, and discuss: the construction of a colour basis that diagonalizes the leading soft function to all orders in perturbation theory; the determination of the two-loop soft anomalous dimension needed for NNLL resummations; and a general formula that provides all logarithmically enhanced O(alpha_s^2) correction requiring as process-independent input only the one-loop hard matching coefficients.