MUPA · Blueprint for a multi-parton model

Understanding the physics of hadronic scattering is key to our ability to produce accurate calculations of collider observables. The current approach maps the problem to perturbative parton scattering by means of the parton model and jet physics. However, the resulting framework offers no reliable means of quantifying power corrections, and its sensitivity to the intricacies of infrared physics makes it challenging to calculate scattering observables at high orders in the perturbative expansion. These constraints constitute important bottlenecks for the production of increasingly more precise collider predictions — the former by introducing susceptibility to uncontrolled effects and the latter by curtailing the perturbative accuracy.This project introduces a new approach, the Multi-Parton model, to describe the infrared behaviour of colliding protons. Centred on a new way to correlate the physics of high-energy partons with that of hadrons, this method considers the scattering of all partons within a hadron, as opposed to just one, as in the parton model. It introduces a fresh perspective on Multi-Partonic Interactions and provides a stage for the estimation of theoretical uncertainties due to power-corrections — both of which are of increasing phenomenological relevance for current and future predictions. Finally, the resulting framework enables systematic Monte Carlo integration of fixed-order hadronic cross-sections, thereby providing a competitive approach to the computation of physical observables with a strong potential for automation. To achieve my objectives, I will utilise established methods for the analytic calculation of fixed-order cross-sections. Using results obtained in this way, I will be able to test the theoretical properties of the model in a controlled setting. Drawing on my prior research on the Local Unitarity formalism, I will generate numerical results that will serve as a proof-of-concept for the automated computational technology.