Browsing Bergen Open Research Archive by Author "Øgreid, Odd Magne"
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Complex S3symmetric 3HDM
Kunčinas, A.; Øgreid, Odd Magne; Osland, Per; Rebelo, M.N. (Journal article; Peer reviewed, 2023)CP violation plays a very important role in nature with implications both for Particle Physics and for Cosmology. Accounting for the observed matterantimatter asymmetry of the Universe requires the existence of new sources ... 
CP violation in extended Higgs sectors
Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 20180824)We discuss how one can identify CP violation (and conservation) in multiHiggsdoublet 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
EmmanuelCosta, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (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 twoHiggsdoublet ... 
The CPsymmetries of the 2HDM
Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Journal article; Peer reviewed, 2020)We discuss the three different classes of CPsymmetries that can be realized in a twoHiggsdoublet model, CP1, CP2 and CP3. We express conditions for realizing these symmetries in terms of masses and couplings of the ... 
CPViolation in the \(ZZZ\) and \(ZWW\) vertices at \(e^+e^\) colliders in TwoHiggsDoublet Models
Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 201605)We discuss possibilities of measuring CP violation in the TwoHiggsDoublet Model by studying effects of oneloop generated \(ZZZ\) and \(ZWW\) vertices. We discuss a set of CPsensitive asymmetries for \(ZZ\) and \(W^+W^\) ... 
Dark matter in a CPviolating threeHiggsdoublet model with S3 symmetry
Kuncinas, Anton; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Journal article; Peer reviewed, 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 threeHiggsdoublet models with S3 symmetry
Khater, W.; Kunčinas, A.; Øgreid, Odd Magne; Osland, Per; Rebelo, M.N. (Journal article; Peer reviewed, 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, 201401)We have investigated a TwoHiggsDoublet 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, 201812)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 ... 
Light scalars in the Weinberg 3HDM potential with spontaneous CP violation
Plantey, Robin Maurice Yves; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N.; Solberg, Marius (Journal article; Peer reviewed, 2022)The Z2×Z2symmetric 3HDM potential, sometimes called Weinberg's 3HDM potential, can accommodate both explicit and spontaneous CP violation as well as natural flavour conservation and is hence relevant for studies of CP ... 
Measuring CP violation in twoHiggsdoublet models in light of the LHC Higgs data
Grzadkowski, Bohdan; Øgreid, Odd Magne; Osland, Per (Peer reviewed; Journal article, 201411)In TwoHiggsDoublet 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 ... 
S3inspired threeHiggsdoublet 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 S3symmetric threeHiggsdoublet 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 multiHiggs models
Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 201708)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 ... 
Softly broken symmetries in the 2HDM — an invariant formulation
Ferreira, P.M.; Grzadkowski, B.; Øgreid, Odd Magne; Osland, Per (Journal article; Peer reviewed, 2023)Soft breaking of a symmetry requires an invariance of the dimension4 part of the Lagrangian and nontrivial variation of the lowerdimensional part. However, in general, separation between the dim4 and lowerdimensional ... 
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 twoHiggsdoublet 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 S3symmetric scalar sector
EmmanuelCosta, David; Øgreid, Odd Magne; Osland, Per; Rebelo, Margarida N. (Peer reviewed; Journal article, 201602)We present a detailed study of the vacua of the S3symmetric threeHiggsdoublet potential, specifying the region of parameters where these minimisation solutions occur. We work with a CP conserving scalar potential and ... 
Spontaneous symmetry breaking in threeHiggsdoublet \(S_3\)symmetric models
EmmanuelCosta, 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, 20190104)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 (Journal article; Peer reviewed, 2021)Symmetries of the TwoHiggsDoublet Model (2HDM) potential that can be extended to the whole Lagrangian, i.e. the CPsymmetries CP1, CP2, CP3 and the Higgsfamily symmetries Z2, U(1) and SO(3) are discussed. Sufficient and ...