Z. Rezaei

Isfahan University of Technology, Eşfahān, Ostan-e Esfahan, Iran

Are you Z. Rezaei?

Claim your profile

Publications (3)1.13 Total impact

  • Source
    M. Haghighat, I. Motie, Z. Rezaei
    [Show abstract] [Hide abstract]
    ABSTRACT: We consider the Lorentz violated extension of the standard model. In this framework, there are terms that explicitly violate CP-symmetry. We examine the CPT-even $d_{\mu\nu}$-term to find the electric dipole moment of charged leptons. We show that the form factors besides the momentum transfer, depend on a new Lorentz-scalar, constructing by $d_{\mu\nu}$ and the four momenta of the lepton, as well. Such an energy dependence of the electric dipole form factor leads to an enhancement of the lepton electric dipole moment at high energy, even at the zero momentum transfer. We show that at $\frac{|d|p^2}{m^2_l}\sim 1$ the electric dipole moment of the charged lepton can be as large as $10^{-14} e\,\,cm$.
    International Journal of Modern Physics A 08/2013; 28(24). · 1.13 Impact Factor
  • Source
    Massimo Giovannini, Zhara Rezaei
    [Show abstract] [Hide abstract]
    ABSTRACT: The properties of magnetized plasmas are always investigated under the hypothesis that the relativistic inhomogeneities stemming from the fluid sources and from the geometry itself are sufficiently small to allow for a perturbative description prior to photon decoupling. The latter assumption is hereby relaxed and pre-decoupling plasmas are described within a suitable expansion where the inhomogeneities are treated to a given order in the spatial gradients. It is argued that the (general relativistic) gradient expansion shares the same features of the drift approximation, customarily employed in the description of cold plasmas, so that the two schemes are physically complementary in the large-scale limit and for the low-frequency branch of the spectrum of plasma modes. The two-fluid description, as well as the magnetohydrodynamical reduction, are derived and studied in the presence of the spatial gradients of the geometry. Various solutions of the coupled system of evolution equations in the anti-Newtonian regime and in the quasi-isotropic approximation are presented. The relation of this analysis to the so-called separate Universe paradigm is outlined. The evolution of the magnetized curvature perturbations in the nonlinear regime is addressed for the magnetized adiabatic mode in the plasma frame.
    Physical review D: Particles and fields 02/2011; 83(8).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: According to the standard cosmology, near the last scattering surface, the photons scattered via Compton scattering are just linearly polarized and then the primordial circular polarization of the CMB photons is zero. In this work we show that CMB polarization acquires a small degree of circular polarization when a background magnetic field is considered or the quantum electrodynamic sector of standard model is extended by Lorentz-noninvariant operators as well as noncommutativity. The existence of circular polarization for the CMB radiation may be verified during future observation programs and it represents a possible new channel for investigating new physics effects. Comment: 28 pages, v3, Phys. Rev. D 81, 084035 (2010)
    Physical review D: Particles and fields 12/2009;