Prof. Gavin Salam FRS

Abstract:

Parton showers are among the most widely used tools in collider physics. Despite their key importance, none so far have been able to demonstrate accuracy beyond a basic level known as leading logarithmic order, with ensuing limitations across a broad spectrum of physics applications. In this Letter, we propose criteria for showers to be considered next-to-leading logarithmic accurate. We then introduce new classes of shower, for final-state radiation, that satisfy the main elements of these criteria in the widely used large-NC limit. As a proof of concept, we demonstrate these showers’ agreement with all-order analytical next-to-leading logarithmic calculations for a range of observables, something never so far achieved for any parton shower.