Infrared subtraction at next-to-next-to-leading order for gluonic initial states

In this thesis we describe a procedure for isolating the infrared singularities present in gluonic scattering amplitudes at next-to-leading and next-to-next-to-leading order. We adopted the antenna subtraction framework which has been successfully applied to the calculation of NNLO corrections to the 3-jet cross section and related event shape distributions in electron-positron annihilation. We consider processes with coloured particles in the initial state, and in particular two-jet production in hadron-hadron collisions at accelerators such as the Large Hadron Collider (LHC). We derive explicit formulae for subtracting the single and double unresolved contributions from the double radiation gluonic processes using antenna functions with initial state partons. We show numerically that the subtraction term effectively approximates the matrix element in the various single and double unresolved configurations.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Durham University

Year dc:date.issued

2010

Author dc:creator

• Pires, Joao Nuno R. G.