Quark/gluon tagging: machine learning for particle physics using R, 16th Zimányi Winter School on Heavy-Ion Physics, 5–9 December 2016

The power to discriminate between light-quark jets and gluon jets would have a huge impact on many searches for new physics at CERN and beyond. This talk will present a walk-through of the development of a prototype machine learning classifier for differentiating between quark and gluon jets at experiments like those at the Large Hadron Collider at CERN. A new fast feature selection method that combines information theory and graph analytics will be outlined. This method has found new variables that promise significant improvements in discrimination power. The prototype jet tagger is simple, interpretable, parsimonious, and computationally extremely cheap, and therefore might be suitable for use in trigger systems for real-time data processing. Nested stratified k-fold cross validation was used to generate robust estimates of model performance. The data analysis was performed entirely in the R statistical programming language, and is fully reproducible. The entire analysis workflow is data-driven, automated and runs on very modest hardware with no human intervention. New data visualisation techniques will also be introduced.

This was a talk given at the 16th Zimányi Winter School on Heavy-Ion Physics, Wigner Research Centre for Physics, and partly at E?tv?s Loránd University, Budapest, 5–9 December 2016.

The slides for this talk can be found here.