Speaker
Description
Indirect searches for new physics increasingly rely on precise theoretical predictions in the high-energy tails, with Parton Distribution Functions (PDFs) being one of the main bottlenecks.
In this talk, I explore the interplay between the fits of Standard Model Effective Field Theory (SMEFT) Wilson coefficients and PDFs in two key sectors at the LHC, the Drell-Yan and the top sector. I explore two complementary strategies for robust new physics searches: (i) fitting the PDFs and SMEFT parameters simultaneously, and (ii) fitting them separately with a “conservative” determination of the PDFs, using only observables that can safely be considered SM–like. I compare both methodologies in controlled closure tests in a realistic High-Luminosity LHC (HL-LHC) scenario and propose best-practice recommendations for robust indirect new physics searches in the Drell-Yan and top sectors at hadron colliders.
I extend this with the inclusion of low-energy using the CLEW (Collider, Low energy and Electroweak precision) framework to perform a global SMEFT+PDF fit free from flavour assumptions. This demonstrates the impact of low-energy data in improving constraints and lifting degeneracies within SMEFT fits.