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

Area of Science:

• Particle Physics
• High Energy Physics
• Standard Model Physics

Background:

• The Standard Model (SM) of particle physics provides a successful description of fundamental particles and forces.
• However, the SM does not fully explain phenomena like CP-violation.
• The Standard Model effective field theory (SMEFT) framework extends the SM to incorporate potential new physics effects, including CP-violating operators.

Purpose of the Study:

• To investigate the phenomenological consequences of CP-violating structures within the SMEFT framework.
• To derive constraints on these structures using existing Run I LHC data.
• To evaluate the potential of current and future LHC runs to probe CP-violating phenomena, particularly in the Higgs sector.

Main Methods:

• Focusing on operators involving electroweak gauge and Higgs bosons within the SMEFT.
• Deriving constraints from Run I Large Hadron Collider (LHC) data.
• Analyzing both traditional four-lepton final states and novel angular/non-angular observables for CP-violation searches.
• Assessing the sensitivity of future LHC runs at higher energies.

Main Results:

• Constraints on CP-violating operators were derived from Run I LHC data.
• The study demonstrates the potential of differential measurements to enhance sensitivity to CP-violating effects.
• Both established and new observables were considered for probing CP-violation in the Higgs sector.

Conclusions:

• LHC data provides valuable constraints on CP-violating structures in the SMEFT.
• Future LHC runs, utilizing differential information, offer enhanced capabilities to probe CP-violating phenomena.
• The investigation highlights the importance of exploring diverse observables for comprehensive searches for new physics beyond the Standard Model.