Novel angular dependence in Drell-Yan lepton production via dimension-8 operators
Simone Alioli, Radja Boughezal, Emanuele Mereghetti, Frank Petriello
TL;DR
This work investigates how dimension-8 SMEFT operators can imprint new angular structures in Drell-Yan lepton-pair production at the LHC, structures that cannot arise from dimension-6 terms or SM QCD. By classifying operator categories and identifying seven dim-8 operators that generate $l=2$ partial waves (and, upon interference, permit $l=3$ harmonics), the authors demonstrate a smoking-gun signature of high-scale physics. They propose extending the conventional Collins-Soper angular basis with new $B_i^{e/o}$ coefficients to capture these effects and provide a numerical study at $\sqrt{s}=14$ TeV showing potential observability for realistic Wilson coefficients, given sufficient luminosity. The work offers concrete guidance for experimental analyses and connects the signature to plausible UV completions, such as vector leptoquarks, highlighting the practical impact of higher-dimensional EFT effects on collider phenomenology.
Abstract
We study the effects of dimension-8 operators on Drell-Yan production of lepton pairs at the Large Hadron Collider (LHC). We identify a class of operators that leads to novel angular dependence not accounted for in current analyses. The observation of such effects would be a smoking-gun signature of new physics appearing at the dimension-8 level. We propose an extension of the currently used angular basis and show that these effects should be observable in future LHC analyses for realistic values of the associated dimension-8 Wilson coefficients.