2018/10/31 by Joel Oredsson, Johan Rathsman · 20 citations
Physics and Astronomy · #Ansatz #Black Holes and Theoretical Physics #Chiral symmetry breaking #Cosmology and Gravitation Theories #Electroweak interaction #Geometry #Higgs boson #Mathematical physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Renormalization group #Scalar (mathematics) #Spontaneous symmetry breaking #Symmetry breaking #Yukawa potential #hep-ph
paper · pdf · doi:10.1007/jhep02(2019)152
published in Journal of High Energy Physics 2019(2) (Springer Nature) · 33 pages, journal version
openalex created_date 2018/10/12 · openalex publication_date 2019/02/01 · arxiv created 2019/03/07 · arxiv updated 2019/03/27 · openalex updated_date 2026/08/06
A bstract We investigate the effects of a ℤ 2 symmetry in the CP <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>C</mml:mi> <mml:mi>P</mml:mi> </mml:math> -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.