2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42488We study the azimuthal correlation of hadron pairs produced in hadron-hadron collisions in the framework of perturbative QCD. We concentrate our attention on the `almost back-to-back' region where resummation of large logarithms due to soft and/or collinear radiation are shown to play an important role. Our aim is to perform perturbative resummation at single logarithmic accuracy.4 pages. LaTeX (stylefile included). Talk given at the 38th Rencontres de Moriond - QCD and Hadronic Interactions, Les Arcs, France, 22-29 March 2003High Energy Physics - Phenomenologytext