Symmetries of two Higgs doublet model and CP violation

By I. Ginzburg, M. Krawczyk. 2004

194 citations recorded by the source corpus.

We use the invariance of a physical picture under a change of Lagrangian, the reparameterization invariance in the space of Lagrangians and its particular case--the rephrasing invariance--for analysis of the two-Higgs-doublet extension of the standard model. We found that some parameters of theory like tan{beta} are reparameterization dependent and therefore cannot be fundamental. We use the Z{sub 2} symmetry of the Lagrangian, which prevents a {phi}{sub 1}{r_reversible}{phi}{sub 2} transition, and the different levels of its violation, soft and hard, to describe the physical content of the model. In general, the broken Z{sub 2} symmetry allows for a CP violation in the physical Higgs sector. We argue that the two-Higgs-doublet model with a soft breaking of Z{sub 2} symmetry is a natural model in the description of electroweak symmetry breaking. To simplify the analysis, we choose among different forms of Lagrangian describing the same physical reality a specific one, in which the vacuum expectation values of both Higgs fields are real. A possible CP violation in the Higgs sector is described by using a two-step procedure with the first step identical to a diagonalization of the mass matrix for CP-even fields in the CP-conserving case. We find a very simple, necessary,more » and sufficient condition for a CP violation in the Higgs sector. We determine the range of parameters for which CP violation and flavor-changing neutral current effects are naturally small--it corresponds to a small dimensionless mass parameter {nu}=Rem{sub 12}{sup 2}/(2v{sub 1}v{sub 2}). We show that for small {nu} some Higgs bosons can be heavy--with mass up to about 0.6 TeV--without violating of the unitarity constraints. If {nu} is large, all Higgs bosons except one can be arbitrarily heavy. We discuss, in particular, main features of this case, which corresponds for {nu}{yields}{infinity} to a decoupling of heavy Higgs bosons. In the model II for Yukawa interactions we obtain the set of relations among the couplings to gauge bosons and to fermions which allows us to analyze different physical situations (including CP violation) in terms of these very couplings, instead of the parameters of Lagrangian.« less

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/90091ab8de5ca357c4c84a5207a0e0ed067fd66b

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Nuclear and High Energy Physics

Citations in the corpus

Maximally symmetric two Higgs doublet model with natural standard model alignment (2014, background): “14), we have also included the possibility of decoupling via a large λ5 coupling [25].”
Physics at a 100 TeV pp collider: Higgs and EW symmetry breaking studies (2016, background): “In a general twoHiggs doublet model it is possible to satisfy β − α ≈ π/2, while still keeping light the new Higgs states [415, 417, 500, 501].”
Vacuum stability conditions from copositivity criteria (2012, methodology): “where we have parameterised the field bilinears as [33]”
Building and testing models with extended Higgs sectors (2017, background): “Envisioning renormalization procedure, [185, 186] argued that the most general 2HDM scalars sector should also include the offdiagonal kinetic terms κ(Dμφ1)(Dφ2) + h.”
A comprehensive approach to new physics simulations (2009, background): “e this transformation leaves the gauge-covariant kinetic energy terms invariant. This notion of basis invariance has been emphasized in Ref. [95] and considered in great detail more recently in Refs. [96, 97, 98]. Since a given set of Lagrangian parameter values is only meaningful for a given basis,”
Vacuum stability of a general scalar potential of a few fields (2016, background): “2+ 3h 2h2 + 4ˆ 2h2h2 + 5ˆ 2 cos2˚h2 1h 2 + 2 6ˆcos˚h3 1h2 + 27ˆcos˚h1h 3 2; (65) where we have taken the potentially complex couplings 5, 6 and 7 real and parameterised the eld bilinears as [39] jH 1j2 = h2; jH2j2 = h2 2: H y 1H2 = h1h2ˆe i˚: (66) The orbit space parameter ˆ2[0;1] as implied by th”