The Evolution of Soft Collinear Effective Theory

TL;DR

This paper reviews the development and applications of Soft Collinear Effective Theory (SCET), an effective field theory for QCD processes involving energetic particles and soft radiation, highlighting its role in factorization and resummation in high-energy physics.

Contribution

It provides a comprehensive overview of SCET's fundamental concepts and its recent applications in analyzing multi-scale QCD processes in various high-energy collision experiments.

Findings

SCET enables factorization of complex QCD cross sections into simpler functions.

SCET allows resummation of large logarithms via renormalization group evolution.

The theory offers insights into nonperturbative effects in high-energy collisions.

Abstract

Soft Collinear Effective Theory (SCET) is an effective field theory of Quantum Chromodynamics (QCD) for processes where there are energetic, nearly lightlike degrees of freedom interacting with one another via soft radiation. SCET has found many applications in high-energy and nuclear physics, especially in recent years the physics of hadronic jets in $e^+e^-$, lepton-hadron, hadron-hadron, and heavy-ion collisions. SCET can be used to factorize multi-scale cross sections in these processes into single-scale hard, collinear, and soft functions, and to evolve these through the renormalization group to resum large logarithms of ratios of the scales that appear in the QCD perturbative expansion, as well as to study properties of nonperturbative effects. We overview the elementary concepts of SCET and describe how they can be applied in high-energy and nuclear physics.