• CP violation in extended Higgs sectors 

      Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2018-08-24)
      We discuss how one can identify CP violation (and conservation) in multi-Higgs-doublet potentials. After a brief review of CP violation in the 2HDM, we refer to the fact that for NHDM with N ≥ 3 the well known methods ...
    • CP Violation in the scalar sector 

      Emmanuel-Costa, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Conference object; Peer reviewed; Journal article, 2016)
      Models with an extended scalar sector may in principle provide new sources of CP violation originating in the scalar potential. One of the simplest ways to implement this idea is to have CP violation in a two-Higgs-doublet ...
    • The CP-symmetries of the 2HDM 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Journal article; Peer reviewed, 2020)
      We discuss the three different classes of CP-symmetries that can be realized in a two-Higgs-doublet model, CP1, CP2 and CP3. We express conditions for realizing these symmetries in terms of masses and couplings of the ...
    • CP-Violation in the \(ZZZ\) and \(ZWW\) vertices at \(e^+e^-\) colliders in Two-Higgs-Doublet Models 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2016-05)
      We discuss possibilities of measuring CP violation in the Two-Higgs-Doublet Model by studying effects of one-loop generated \(ZZZ\) and \(ZWW\) vertices. We discuss a set of CP-sensitive asymmetries for \(ZZ\) and \(W^+W^-\) ...
    • Diagnosing CP properties of the 2HDM 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2014-01)
      We have investigated a Two-Higgs-Doublet Model (2HDM), focusing on CP violation. Various scenarios with spontaneous and explicit breaking of CP have been considered. Some features of CP violation related to a choice of the ...
    • Heavy Higgs boson decays in the alignment limit of the 2HDM 

      Øgreid, Odd Magne; Osland, Per; Grzadkowski, Bohdan; Haber, Howard (Peer reviewed; Journal article, 2018-12)
      The Standard Model (SM)-like couplings of the observed Higgs boson impose strong constraints on the structure of any extended Higgs sector. We consider the theoretical properties and the phenomenological implications of a ...
    • Implications of symmetries in the scalar sector 

      Haber, Howard E.; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Journal article; Peer reviewed, 2020)
      Symmetries play a very important rôle in Particle Physics. In extended scalar sectors, the existence of symmetries may permit the models to comply with the experimental constraints in a natural way, and at the same time ...
    • Measuring CP violation in two-Higgs-doublet models in light of the LHC Higgs data 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2014-11)
      In Two-Higgs-Doublet models, the conditions for CP violation can be ex- pressed in terms of invariants under U(2) rotations among the two SU(2) Higgs doublet fields. In order to design a strategy for measuring the invariants ...
    • S3-inspired three-Higgs-doublet models: A class with a complex vacuum 

      Kuncinas, Anton; Osland, Per; Øgreid, Odd Magne; Rebelo, Margarida N. (Journal article; Peer reviewed, 2020)
      In this paper we analyze in detail an S3-symmetric three-Higgs-doublet model with a specific vacuum configuration. This analysis allows us to illustrate important features of models with several Higgs doublets, such as the ...
    • A simple method to detect spontaneous CP violation in multi-Higgs models 

      Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2017-08)
      For models with several Higgs doublets we present an alternative method to the one proposed by Branco, Gerard and Grimus, in 1984, to check whether or not CP is spontaneously violated in the Higgs potential. The previous ...
    • Some properties of the generic 2HDM in the alignment limit 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2017)
      We discuss various properties of the generic two-Higgs-doublet extension of the Standard Model focusing on the region of parameter space known as the alignment limit. We emphasize that in the alignment limit in order to ...
    • Spontaneous symmetry breaking in the S3-symmetric scalar sector 

      Emmanuel-Costa, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2016-02)
      We present a detailed study of the vacua of the S3-symmetric three-Higgs-doublet potential, specifying the region of parameters where these minimisation solutions occur. We work with a CP conserving scalar potential and ...
    • Spontaneous symmetry breaking in three-Higgs-doublet \(S_3\)-symmetric models 

      Emmanuel-Costa, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2017)
      The talk summarises work done by the authors consisting of a detailed study of the possible vacua in models with three Higgs doublets with \(S_3\) symmetry and without explicit CP violation. Different vacua require special ...
    • Symmetries and mass degeneracies in the scalar sector 

      Haber, Howard E.; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2019-01-04)
      We explore some aspects of models with two and three SU(2) scalar doublets that lead to mass degeneracies among some of the physical scalars. In Higgs sectors with two scalar doublets, the exact degeneracy of scalar masses, ...
    • Testing the presence of CP violation in the 2HDM 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Conference object; Peer reviewed; Journal article, 2015-04-27)
      We review CP properties of the Two-Higgs-Doublet model. In particular, we show that sponta- neous CP violation occurs in the parameter space on the border between regions allowing explicit CP violation and those where there ...
    • Update on the CP-Violating Inert-Doublet Model 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per; Pukhov, Alexander; Purmohammadi, Mahdi (Conference object; Peer reviewed; Journal article, 2012)
      We have updated a recently proposed extension of the Inert Doublet Model. The extension amounts to the addition of an extra non-inert scalar doublet. The model thus offers a possibility of CP violation in the scalar sector ...