Calculation of Leading Power Jets in Soft-Collinear Effective Theory

Abstract

The importance of Soft Collinear Effective Theory (SCET) arises from its ability to address the challenges posed by phenomena involving disparate energy scales, where fixed/finite order perturbation theory fails due to the emergence of large logarithms. SCET provides a useful framework for breaking down the calculations into different components that depend on single energy scales, i.e. for derivations of factorisation theorems. The all-order expressions can then be obtained using scale evolution by solving the renormalization group equations (RGEs) for each of the pieces appearing in the factorisation formula. This step is known as resummation. In this master thesis presentation, I delve into the construction of SCET, focusing on the derivation of the leading power Lagrangian and the calculation of leading power jet functions with the SCET Lagrangian as well as regular QCD Lagrangian and compare the results.