Probing CP-violating Higgs and gauge boson couplings in the Standard Model effective field theory

TL;DR

This paper investigates potential CP-violating effects in Higgs and gauge boson interactions within the Standard Model effective field theory, using LHC data and proposing new observables for future exploration.

Contribution

It introduces a comprehensive analysis of CP-violating operators involving electroweak bosons, deriving constraints from Run I data and highlighting the importance of differential measurements for future searches.

Findings

Current LHC data constrains certain CP-violating operators.

Differential observables enhance sensitivity to CP-violation.

Future high-energy runs can further probe CP-violating phenomena.

Abstract

We study the phenomenological consequences of several $CP$-violating structures that could arise in the Standard Model effective field theory framework. Focusing on operators involving electroweak gauge and/or Higgs bosons, we derive constraints originating from Run I LHC data. We then study the capabilities of the present and future LHC runs at higher energies to further probe associated CP-violating phenomena and we demonstrate how differential information can play a key role. We consider both traditional four-lepton probes of CP-violation in the Higgs sector and novel new physics handles based on varied angular and non-angular observables.