Verso uno Schema di Sottrazione Universale per la QCD a NNLO

In this thesis work, we present the current developments of the Local Analytic Sector Subtraction Method for the management of infrared-safe final-state massless partons processes at next-to-next-to-leading order in perturbative QCD. Beginning with a general introduction on the main features of QCD, we introduce the theme of infrared divergences and the basic ideas of the subtraction schemes. A brief overview of some subtraction procedures already available in literatire, namely the Frixione-Kunszt-Signer Subtraction, the Catani-Seymour Subtraction and the CoLoRFul Subtraction is presented to introduce the Local Analytic Sector Subtraction at NNLO. We then recall the well established basic ideas of the method, which attempts to conjugate the minimal local counterterm structure and the simplifications following from analytic integration of the counterterms. We propose new definitions for several local counterterms, verifying they reproduce the correct infrared behavior and that their analytic integration displays all the features expected in the subtraction framework. The complete definition and integration of the soft mixed double-unresolved infrared counterterm is carried out and the finiteness of corresponding part of the subtraction formula is verified.