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... (More)
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.
@article{97404f8a-c903-4e71-865a-eaf6663a3666,
abstract = {{<p><br>
We investigate the effects of a ℤ <br>
<sub>2</sub><br>
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 <br>
<sub>2</sub><br>
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 <br>
<sub>2</sub><br>
symmetric 2HDM is very constrained, a soft breaking of the ℤ <br>
<sub>2</sub><br>
symmetry extends the valid parameter space regions. The effects of a hard ℤ <br>
<sub>2</sub><br>
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 <br>
<sub>2</sub><br>
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 <br>
<sub>2</sub><br>
breaking in the Yukawa sector at most gives moderate ℤ <br>
<sub>2</sub><br>
breaking in the potential; whereas the FCNCs can become quite sizable far away from the ℤ <br>
<sub>2</sub><br>
symmetric regions. <br>
</p>}},
author = {{Oredsson, Joel and Rathsman, Johan}},
issn = {{1029-8479}},
keywords = {{Beyond Standard Model; Higgs Physics}},
language = {{eng}},
month = {{02}},
number = {{2}},
publisher = {{Springer}},
series = {{Journal of High Energy Physics}},
title = {{ℤ
<sub>2</sub>
breaking effects in 2-loop RG evolution of 2HDM}},
url = {{http://dx.doi.org/10.1007/JHEP02(2019)152}},
doi = {{10.1007/JHEP02(2019)152}},
volume = {{2019}},
year = {{2019}},
}