Probing Flavor Non-Universal Theories Through Higgs Physics at the LHC and Future Colliders

TL;DR

This paper investigates how flavor non-universal new physics affecting Higgs couplings can be constrained using boosted Higgsstrahlung events at the LHC and future colliders, providing competitive bounds with electroweak precision tests.

Contribution

It introduces a framework to probe flavor-violating operators via Higgs processes at colliders, including projections of sensitivity and comparison with existing constraints.

Findings

Projected sensitivity to new physics scale at HL-LHC and future colliders.

High energy $Zh$ process offers unique constraints on flavor-violating operators.

Complementarity with FCNC constraints and exotic Higgs decay channels.

Abstract

We explored the possibility that Higgs coupling to new physics violates flavor universality. In particular, we parameterize such models with dimension-six effective operators which modify the coupling between the first generation quarks, Higgs boson, and $Z$ boson. Through the use of boosted Higgsstrahlung events at both the HL-LHC and potential future hadron colliders, as well as existing ATLAS data for background estimates, we projected constraints on the scale of new physics as a function of the Wilson coefficient. The high energy $Zh$ process will provide unique information about these class of operators, and the sensitivity is competitive with the LEP electroweak precision measurements. We include different scenarios of the overall systematic uncertainties and the PDF uncertainties when presenting the projected sensitivities. We also discuss the constraints from FCNCs to these flavor-violating models and the complementarity of the exotic Higgs decay to the $Zh$ process.