Flavor at the Crossroads

Semileptonic transitions at high-pT

22 Apr 2022, 16:00

1h

02.430 (Mainz Institute for Theoretical Physics, Johannes Gutenberg University)

Speaker

Wilsch Felix (University of Zurich)

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 neutral and charged current Drell-Yan processes contributing to these high-pT tails 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) or to the coupling constants of tree-level mediators present in concrete NP models. 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 Lagrangian by using a consistent expansion of the observables in the NP scale $\mathrm{\Lambda }$ up to order $\mathcal{O}({\mathrm{\Lambda }}^{-4})$. We also compare these results with the truncation at order $\mathcal{O}({\mathrm{\Lambda }}^{-2})$ or when considering only dimension six operators. 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 semileptonic effective operators or NP coupling constants. 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.

Presentation materials

MITP_2022.pdf