• Charged-Higgs production in the Two-Higgs-doublet model — the τ ν channel 

      Basso, Lorenzo; Osland, Per; Pruna, Giovanni Marco (Peer reviewed; Journal article, 2015-06-15)
      We update the allowed parameter space of the CP-violating 2HDM with Type II Yukawa couplings, that survives the current experimental and theoretical constraints on the model. For a representative set of allowed parameter ...
    • Cosmic Ray Signatures from Decaying Gravitino Dark Matter 

      Bomark, Nils-Erik; Lola, Smaragda; Osland, Per; Raklev, Are R. (Conference object; Journal article, 2009)
      We study the charged cosmic rays arising from the slow decay of gravitino dark matter within supersymmetric scenarios with trilinear R-parity violation. It is shown that operators of the LLE type can very well account for ...
    • 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 ...
    • Exploring the CP-violating Inert-Doublet Model 

      Grzadkowski, B.; Ogreid, Odd Magne; Osland, Per; Pukhov, A.; Poormohammadi, Mahdi (Peer reviewed; Journal article, 2011-06-01)
      We have explored properties of an extension of the Inert Doublet Model by the addition of an extra non-inert scalar doublet. The model offers a possibility of CP violation in the scalar sector and a candidate for the Dark ...
    • Flavour structure of R-violating neutralino decays at the LHC 

      Bomark, Nils-Erik; Choudhury, Debajyoti; Lola, Smaragda; Osland, Per (Peer reviewed; Journal article, 2011-07-15)
      We study signatures of R-parity violation in the production of supersymmetric particles at the LHC, and the subsequent decay of the lightest neutralino being the end product of a supersymmetric cascade decay. In doing so, ...
    • Gravitino dark matter and the flavour structure of R-violating operators 

      Bomark, Nils-Erik; Lola, Smaragda; Osland, Per; Raklev, Are Reinert (Peer reviewed; Journal article, 2009-06-15)
      We study gravitino dark matter and slow gravitino decays within the framework of R-violating supersymmetry, with particular emphasis on the flavour dependence of the branching ratios and the allowed R-violating couplings. ...
    • 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 ...
    • The Higgs-like boson spin from the center–edge asymmetry in the diphoton channel at the LHC 

      Osland, Per; Pankov, Alexander A.; Tsytrinov, Andrej V. (Peer reviewed; Journal article, 2015-05-07)
      We discuss the discrimination of the 125 GeV spin-parity 0+ Higgs-like boson observed at the LHC, decaying into two photons, H→γγ, against the hypothesis of a minimally coupled JP=2+ narrow diphoton resonance with the same ...
    • High-precision limits on W–W′and Z–Z′ mixing from diboson production using the full LHC Run 2 ATLAS data set 

      Pankov, A.A.; Osland, Per; Serenkova, I.A.; Bednyakov, V.A. (Journal article; Peer reviewed, 2020)
      The full ATLAS Run 2 data set with time-integrated luminosity of 139fb−1 in the diboson channels in hadronic final states is used to probe a simple model with an extended gauge sector (EGM), proposed by Altarelli et al., ...
    • 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 ...
    • Improved bounds on W−W′ mixing with ATLAS resonant WZ production data at the LHC at √s=13  TeV 

      Serenkova, IA; Osland, Per; Pankov, Alexander A (Peer reviewed; Journal article, 2019)
      New charged vector bosons W ′ decaying into gauge boson pairs W Z are predicted in many scenarios of new physics, including models with an extended gauge sector (EGM). Due to the large variety of models (other unification ...
    • Improved constraints on the mixing and mass of Z ′ bosons from resonant diboson searches at the LHC at √ s = 13 TeV and predictions for Run II 

      Bobovnikov, ID; Osland, Per; Pankov, AA (Peer reviewed; Journal article, 2018)
      New neutral vector bosons Z ′ decaying to charged gauge boson pairs W + W − are predicted in many scenarios of new physics, including models with an extended gauge sector such as E 6 , left-right symmetric Z ′ LRS and the ...
    • Long lived charginos in Natural SUSY? 

      Bomark, Nils-Erik; Kvellestad, Anders; Lola, Smaragda; Osland, Per; Raklev, Are (Peer reviewed; Journal article, 2014-05-05)
      Supersymmetric models with a small chargino-neutralino mass difference, and as a result metastable charginos, have been a popular topic of investigation in collider phenomenology. The possibility of a chargino lighter than ...
    • 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 ...
    • Photon, neutrino and charged particle spectra from R-violating gravitino decays 

      Bomark, Nils-Erik; Lola, Smaragda; Osland, Per; Raklev, Are Reinert (Peer reviewed; Journal article, 2010-03-22)
      We study photonic, neutrino and charged particle signatures from slow decays of gravitino dark matter in supersymmetric theories where R-parity is explicitly broken by trilinear operators. Photons and (anti-)fermions from ...
    • Probing the charged Higgs boson at the LHC in the CP-violating type-II 2HDM 

      Basso, L.; Lipniacka, Anna; Moretti, S.; Osland, Per; Pruna, G. M.; Poormohammadi, Mahdi (Peer reviewed; Journal article, 2012-11-05)
      We present a phenomenological study of a CP-violating two-Higgs-doublet Model with type-II Yukawa couplings at the Large Hadron Collider (LHC). In the light of recent LHC data, we focus on the parameter space that survives ...