# Johan Rathsman

Senior lecturer

## ℤ _{2} breaking effects in 2-loop RG evolution of 2HDM

Author

## Summary, in English

We investigate the effects of a ℤ _{2}

symmetry in the CP-conserving Two-Higgs-Doublet-Model (2HDM); which is often imposed to prevent Flavor-Changing-Neutral-Currents (FCNCs) at tree-level. Specifically, we analyze how a breaking of the ℤ _{2}

symmetry spreads during renormalization group evolution; employing general 2-loop renormalization group equations that we have derived. Evolving the model from the electroweak to the Planck scale, we find that while the case of an exact ℤ _{2}

symmetric 2HDM is very constrained, a soft breaking of the ℤ _{2}

symmetry extends the valid parameter space regions. The effects of a hard ℤ _{2}

breaking in the scalar sector as well as the stability of the flavor alignment ansatz are also investigated. We find that while a hard breaking of the ℤ _{2}

symmetry in the potential is problematic, since it speeds up the growth of quartic couplings, the generated FCNCs are heavily suppressed. Conversely, we also find that hard ℤ _{2}

breaking in the Yukawa sector at most gives moderate ℤ _{2}

breaking in the potential; whereas the FCNCs can become quite sizable far away from the ℤ _{2}

symmetric regions.

Department/s

- Theoretical Particle Physics

Publishing year

2019-02-22

Language

English

Publication/Series

Journal of High Energy Physics

Volume

2019

Issue

2

Document type

Journal article

Publisher

Springer

Topic

- Subatomic Physics

Keywords

- Beyond Standard Model
- Higgs Physics

Status

Published

ISBN/ISSN/Other

- ISSN: 1029-8479