The Matrix Element Method and QCD Radiation

TL;DR

This paper enhances the matrix element method for particle physics analysis by incorporating QCD radiation effects, leading to more accurate mass measurements in complex final states at the LHC.

Contribution

It introduces new methods to include QCD radiation effects in the matrix element method, improving mass determination accuracy in high-energy collider experiments.

Findings

Significantly improved mass measurement accuracy.

Effective incorporation of QCD radiation effects.

Enhanced analysis techniques for complex final states.

Abstract

The matrix element method (MEM) has been extensively used for the analysis of top-quark and W-boson physics at the Tevatron, but in general without dedicated treatment of initial state QCD radiation. At the LHC, the increased center of mass energy leads to a significant increase in the amount of QCD radiation, which makes it mandatory to carefully account for its effects. We here present several methods for inclusion of QCD radiation effects in the MEM, and apply them to mass determination in the presence of multiple invisible particles in the final state. We demonstrate significantly improved results compared to the standard treatment.