The high-energy tails of charged- and neutral-current Drell-Yan (DY) processes provide important constraints on the light quark and anti-quark parton distribution functions (PDFs) in the large-x region. On the other hand, a hypothetical short-distance new physics would smoothly distort the high-energy tails as described by the Standard Model Effective Field Theory (SMEFT). In this work, we assess for the first time the interplay between PDF and EFT effects in the high-mass Drell-Yan at the LHC. We determine to which extent EFT signals that would manifest themselves in the tails of the Drell-Yan distributions could be reabsorbed into the large-x (anti-)quark PDFs, and present a strategy aimed at disentangling possible New Physics effects from proton structure modifications. We quantify the impact that a consistent joint determination of the PDFs and Wilson coefficients has in two motivated short-distance new physics scenarios: 1) electroweak oblique corrections and 2) four-fermion interactions possibly behind the LHCb anomalies in R(K(∗)). Finally, we present dedicated projections for the High-Luminosity LHC and evaluate its ultimate potential to constrain the EFT parameters, while taking into account potential modifications of the proton structure.
|First author||Juan Rojo|
|Collaboration / Activity||Theoretical Particle Physics|