• 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)
    • Complex S <inf>3</inf>-symmetric 3HDM 

      Kunčinas, A.; Øgreid, Odd Magne; Osland, Per; Rebelo, M.N. (Peer reviewed; Journal article, 2023)
      CP violation plays a very important role in nature with implications both for Particle Physics and for Cosmology. Accounting for the observed matter-antimatter asymmetry of the Universe requires the existence of new sources ...
    • CP violation in extended Higgs sectors 

      Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Journal article; Peer reviewed, 2018)
      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. (Peer reviewed; Journal article, 2016)
    • The CP-symmetries of the 2HDM 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 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)
      We discuss possibilities of measuring CP violation in the Two-Higgs-Doublet Model by studying effects of one-loop generated ZZZ and ZW W vertices. We discuss a set of CP-sensitive asymmetries for ZZ and W+W− production at ...
    • Dark matter in a CP-violating three-Higgs-doublet model with S3 symmetry 

      Kuncinas, Anton; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2022)
      In spite of the success of the Standard Model of particle physics, there are some theoretical predictions which are not yet fully established experimentally, as well as some experimental observations which cannot be fitted ...
    • Dark matter in three-Higgs-doublet models with S <inf>3</inf> symmetry 

      Khater, W.; Kunčinas, A.; Øgreid, Odd Magne; Osland, Per; Rebelo, M.N. (Peer reviewed; Journal article, 2022)
      Models with two or more scalar doublets with discrete or global symmetries can have vacua with vanishing vacuum expectation values in the bases where symmetries are imposed. If a suitable symmetry stabilises such vacua, ...
    • Diagnosing CP properties of the 2HDM 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2014)
    • Heavy Higgs boson decays in the alignment limit of the 2HDM 

      Grzadkowski, Bohdan; Haber, Howard E.; Øgreid, Odd Magne; Osland, Per (Journal article; Peer reviewed, 2018)
      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. (Peer reviewed; Journal article, 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)
    • S3-inspired three-Higgs-doublet models: A class with a complex vacuum 

      Kuncinas, Anton; Osland, Per; Øgreid, Odd Magne; Rebelo, Margarida N. (Peer reviewed; Journal article, 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 ...
    • Softly broken symmetries in the 2HDM — an invariant formulation 

      Ferreira, P.M.; Grzadkowski, B.; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2023)
      Soft breaking of a symmetry requires an invariance of the dimension-4 part of the Lagrangian and non-trivial variation of the lower-dimensional part. However, in general, separation between the dim-4 and lower-dimensional ...
    • Some properties of the generic 2HDM in the alignment limit 

      Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Journal article; Peer reviewed, 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 S 3-symmetric scalar sector 

      Emmanuel-Costa, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2016)
    • Spontaneous symmetry breaking in three-Higgs-doublet S3-symmetric models 

      Emmanuel-Costa, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2017)
    • Symmetries and mass degeneracies in the scalar sector 

      Haber, Howard E.; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Journal article; Peer reviewed, 2019)
      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, ...
    • Symmetries and mass degeneracies in the scalar sector 

      Haber, Howard E.; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 2019)
      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, ...
    • Symmetries of the 2HDM: an invariant formulation and consequences 

      Ferreira, Pedro M.; Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 2021)
      Symmetries of the Two-Higgs-Doublet Model (2HDM) potential that can be extended to the whole Lagrangian, i.e. the CP-symmetries CP1, CP2, CP3 and the Higgs-family symmetries Z2, U(1) and SO(3) are discussed. Sufficient and ...