Basis-independent methods for the two-Higgs-doublet model III: The CP-conserving limit, custodial symmetry, and the oblique parameters S, T, U

By H. Haber, Deva O'Neil. 2010

417 citations recorded by the source corpus.

In the standard model, custodial symmetry is violated by the hypercharge U(1) gauge interactions and the Yukawa couplings, while being preserved by the Higgs scalar potential. In the two-Higgs-doublet model (2HDM), the generic scalar potential introduces new sources of custodial symmetry breaking. We obtain a basis-independent expression for the constraints that impose custodial symmetry on the 2HDM scalar potential. These constraints impose CP-conservation on the scalar potential and vacuum, and in addition add one extra constraint on the scalar potential parameters. We clarify the mass degeneracies of the 2HDM that arise as a consequence of the custodial symmetry. We also provide a computation of the oblique parameters (S, T, and U) for the most general CP-violating 2HDM in the basis-independent formalism. We demonstrate that the 2HDM contributions to T and U vanish in the custodial symmetry limit, as expected. Using the experimental bounds on S and T from precision electroweak data, we examine the resulting constraints on the general 2HDM parameter space.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/664ec493ec1f9e336f1a88da22b871592ce3879f

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

1. Igor P. Ivanov
2. M. Raidal
3. G. Arcadi
4. Abdelhak Djouadi
5. M. Jung
6. A. Pich
7. Georg Weiglein
8. J. Gunion

Citations in the corpus

• Charged-Higgs phenomenology in the aligned two-Higgs-doublet model (2010, background): “The three parameters ςf are also invariant under global SU(2) transformations of the scalar fields φa → φa = Uabφb [25], i.”
• Scrutinizing the alignment limit in two-Higgs-doublet models: m h = 125 GeV (2015, methodology): “The Z2 symmetry guarantees that the neutral Higgs-fermion couplings are (5)The translation between the Higgs and Z2-bases is discussed in detail in [8, 15,18,20].”
• Dark Matter through the Higgs portal (2019, background): “We have assumed from the start the presence of a discrete symmetry [396] which forbids the appearance of two additional couplings λ6 and λ7.”
• ILC Higgs White Paper (2013, background): “In the Higgs basis, the scalar potential is given by [56, 57]:”
• Building and testing models with extended Higgs sectors (2017, methodology): “If one focuses on the scalar sector only, then there exists a large freedom to change the basis in the (φ1, φ2) space, leading to reparametrization of the Higgs potential (the explicit expressions can be found in [185, 194]).”