Speaker
Description
High-pT tail observables at the LHC offer a complementary probe to low-energy experiments for studying the flavor structure of the Standard Model and beyond. We discuss the high-pT tails of neutral- and charged-current Drell-Yan processes to probe New Physics (NP) effects in semileptonic transitions. For this purpose, we describe the relevant cross-sections in terms of general form-factors, which are matched to the Standard Model Effective Field Theory (SMEFT). Contributions from the exchange of new resolved bosonic mediators arising in ultraviolet models are also considered in this form-factor framework. By using the latest run-2 data from LHC on the relevant mono-lepton and di-lepton production channels, we derive constraints on the SMEFT Wilson coefficients using a consistent expansion of the observables in the NP scale $\Lambda$ up to order $\mathcal{O}(\Lambda^{-4})$. At the same time, we also discuss the impact of including dimension eight operators for specific NP scenarios. Furthermore, we present the Mathematica package “HighPT”, which provides a simple way to compute the relevant high-pT tail observables and to extract the complete LHC likelihood for Drell-Yan. To illustrate the relevance of these results, we revisit the leptoquark explanations of the charged-current B-physics anomalies, by exploring the complementarity of our high-pT constraints with the relevant low-energy observables.
