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Register a new userR-parity violating supersymmetric Barr-Zee type contributions to the fermion electric dipole moment with weak gauge boson exchange
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The contribution of the R-parity violating trilinear couplings in the supersymmetric model to the fermion electric dipole moment is analyzed at the two-loop level. We show that in general, the Barr-Zee type contribution to the fermion electric dipole moment with the exchange of W and Z bosons is not small compared to the currently known photon exchange one with R-parity violating interactions. We will then give new upper bounds on the imaginary parts of R-parity violating couplings from the experimental data of the electric dipole moments of the electron and of the neutron. The effect due to bilinear R-parity violating couplings, which needs to be investigated separately, is not included in our analyses.
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The contributions of a second Higgs doublet to the electron electric dipole moment near the heavy Higgs decoupling limit are determined within an effective field theory framework. In models that satisfy the Glashow-Weinberg condition, the leading contributions in this limit at effective dimension six are shown to come from two-loop Barr-Zee diagrams that include the Standard Model-like Higgs boson. Additional diagrams that include heavy Higgs bosons are sub-leading and contribute only at effective dimension eight near the decoupling limit. This simplification implies that to leading order in this limit, contributions of a second Higgs doublet to the electron electric dipole moment can be couched entirely in terms of the ratio of Higgs doublet expectation values and a single universal phase appearing in the effective couplings of the Standard Model-like Higgs boson to fermions, without direct reference to the heavy Higgs boson masses or couplings. The recent bound from the ACME II experiment constrains the phases of the couplings of the Standard Model-like Higgs boson to up-type quarks and leptons at the part per mil level in Type I and IV two Higgs doublet models. In Type II and III models these phases are constrained at the two parts per mil or better level except in a tiny sliver of parameter space with nearly equal Higgs doublet expectation values where destructive interference among contributing diagrams happens to occur. In a more general phenomenological parameterization with individual effective phases in the couplings of the Standard Model-like Higgs boson to third generation fermions and the electron, the top quark and electron coupling phases are constrained at the part per mil level except in tiny slivers of parameter space, while the bottom quark and tau-lepton coupling phases are constrained only at the thirty percent level.
We extend the Zee model, where tiny neutrino masses are generated at the one loop level, to a supersymmetric model with R-parity conservation. It is found that the neutrino mass matrix can be consistent with the neutrino oscillation data thanks to the nonholomorphic Yukawa interaction generated via one-loop diagrams of sleptons. We find a parameter set of the model, where in addition to the neutrino oscillation data, experimental constraints from the lepton flavor violating decays of charged leptons and current LHC data are also satisfied. In the parameter set, an additional CP-even neutral Higgs boson other than the standard-model-like one, a CP-odd neutral Higgs boson, and two charged scalar bosons are light enough to be produced at the LHC and future lepton colliders. If the lightest charged scalar bosons are mainly composed of the SU(2)_L-singlet scalar boson in the model, they would decay into e nu and mu nu with 50% of a branching ratio for each. In such a case, the relation among the masses of the charged scalar bosons and the CP-odd Higgs in the minimal supersymmetric standard model approximately holds with a radiative correction. Our model can be tested by measuring the specific decay patterns of charged scalar bosons and the discriminative mass spectrum of additional scalar bosons.
Considering the CP violating phases, we analyze the neutron electric dipole moment (EDM) in a CP violating supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries(BLMSSM). The contributions from the one loop diagrams and the Weinberg operators are taken into account. Adopting some assumptions on the relevant parameter space, we give the numerical results analysis. The numerical results for neutron EDM can reach $1.05times 10^{-25}(e.cm)$, which is about the experimental upper limit.
We discuss the effect of CP violation in the aligned scenario of the general two-Higgs-doublet model, in which the Higgs potential and the Yukawa interaction provide additional CP-violating phases. An alignment is imposed to the Yukawa interaction in order to avoid dangerous flavor changing neutral currents. The Higgs potential is also aligned such that the coupling constants of the lightest Higgs boson, which is identified as the discovered Higgs boson with the mass of 125 GeV, are the same as those of the standard model. In general, CP-violating phases originated by the Yukawa interaction and the Higgs potential are strongly constrained by the current data for the electric dipole moment (EDM). It is found that in our scenario contributions from the two sources of CP violation can be destructive and consequently their total contribution can satisfy the EDM results, even when each CP-violating phase is large. Such a large CP-violating phase can be tested at collider experiments by looking at the angular distributions of particles generated by the decays of the additional Higgs bosons.
Neutron electric dipole moment (EDM) due to single quark EDM and to the transition EDM is calculated in the minimal supersymmetric standard model. Assuming that the Cabibbo-Kobayashi-Maskawa matrix at the grand unification scale is the only source of CP violation, complex phases are induced in parameters of soft supersymmetry breaking at low energies. Chargino one-loop diagram is found to give the dominant contribution of the order of $10^{-27}sim 10^{-29}:ecdot$cm for quark EDM, assuming the light chargino mass and the universal scalar mass to be $50$ GeV and $100$ GeV, respectively. Therefore the neutron EDM in this class of model is difficult to measure experimentally. Gluino one-loop diagram also contributes due to the flavor changing gluino coupling. The transition EDM is found to give dominant contributions for certain parameter regions.
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