QCD Theory meets Information Theory

TL;DR

This paper introduces a new method that integrates quantum chromodynamics calculations into Monte Carlo simulations using information theory, improving the accuracy and systematic uncertainty estimation of collider event predictions.

Contribution

It develops a systematic reweighting technique based on information theory to incorporate precision QCD calculations into Monte Carlo simulations, applicable to multiple observables simultaneously.

Findings

Achieves consistency with theoretical inputs in precision and uncertainties.

Generates strictly positive weights for statistically powerful simulations.

Highlights the significance of logarithmic moments of event shapes.

Abstract

We present a novel technique to incorporate precision calculations from quantum chromodynamics into fully differential particle-level Monte-Carlo simulations. By minimizing an information-theoretic quantity subject to constraints, our reweighted Monte Carlo incorporates systematic uncertainties absent in individual Monte Carlo predictions, achieving consistency with the theory input in precision and its estimated systematic uncertainties. Our method can be applied to arbitrary observables known from precision calculations, including multiple observables simultaneously. It generates strictly positive weights, thus offering a clear path to statistically powerful and theoretically precise computations for current and future collider experiments. As a proof of concept, we apply our technique to event-shape observables at electron-positron colliders, leveraging existing precision calculations of thrust. Our analysis highlights the importance of logarithmic moments of event shapes, which have not been previously studied in the collider physics literature.