Jennifer Roloff

Any way you slice it: The Lund jet plane as a unique probe of QCD

Abstract:

Jet substructure is a versatile tool which has been applied to identify jets originating from different particles, enabling a wide range of searches and measurements at the LHC. Beyond simply tagging jets, it is also a sensitive probe of QCD across a wide range of energy scales, giving insight into the formation and evolution of jets. While a useful tool, jet substructure is notoriously difficult to describe, and mismodeling of this rich inner structure limits its effectiveness. In this talk, I will discuss how measurements of jet substructure are being used to better understand jet formation and to provide new tests of our theoretical descriptions of these models. In particular, I will cover how measurements of the Lund jet plane have provided a new framework for testing different theoretical effects. I will then use the example of a recent measurement by the ATLAS experiment of the Lund subjet multiplicity to illustrate how these measurements can provide precision tests of parton shower models, enabling more advanced descriptions of jet formation.