Dijet azimuthal correlations in p-p and p-Pb collisions at forward LHC calorimeters

Abstract

We present a state-of-the-art computation for the production of dijets in proton-proton and proton-lead collisions at the LHC, in forward rapidity domains covered by the ATLAS calorimeter and the planned FoCal extension of the ALICE detector. We use the small-x improved TMD (ITMD) formalism, together with collinearly improved TMD gluon distributions and full b-space Sudakov resummation, and discuss nonperturbative corrections due to hadronization and showers using the Pythia event generator. We observe that the production of forward dijets in proton-nucleus collisions at moderately low pT is an excellent probe of saturation effects, and demonstrate that the Sudakov resummation does not alter the suppression of the cross section.