20,886 research outputs found

    On the Form Factors of the $D_{s}^{+}\to \phi\mu^{+}\nu_{\mu} decay

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    We apply the infinite mass effective theory, when a heavy quark mass tends to infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu -- Jona -- Lasinio model with linear realization of chiral U(3)×U(3)U(3)\times U(3) symmetry, to calculate the form factors of the Ds+ϕ μ+ νμD^{\,+}_{\,s}\to\phi~\mu^+~\nu_{\,\mu} decay up to the first order in current ss -- quark mass. The theoretical results are compared with experimental data and found to be in good agreement.Comment: 7pages, latex, no figure

    Gauging N=4 supersymmetric mechanics II: (1,4,3) models from the (4,4,0) ones

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    Exploiting the gauging procedure developed by us in hep-th/0605211, we study the relationships between the models of N=4 mechanics based on the off-shell multiplets (4,4,0) and (1,4,3). We make use of the off-shell N=4, d=1 harmonic superspace approach as most adequate for treating this circle of problems. We show that the most general sigma-model type superfield action of the multiplet (1,4,3) can be obtained in a few non-equivalent ways from the (4,4,0) actions invariant under certain three-parameter symmetries, through gauging the latter by the appropriate non-propagating gauge multiplets. We discuss in detail the gauging of both the Pauli-Gursey SU(2) symmetry and the abelian three-generator shift symmetry. We reveal the (4,4,0) origin of the known mechanisms of generating potential terms for the multiplet (1,4,3), as well as of its superconformal properties. A new description of this multiplet in terms of unconstrained harmonic analytic gauge superfield is proposed. It suggests, in particular, a novel mechanism of generating the (1,4,3) potential terms via coupling to the fermionic off-shell N=4 multiplet (0,4,4).Comment: 27 page

    High harmonic generation in crystals using Maximally Localized Wannier functions

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    In this work, the nonlinear optical response, and in particular, the high harmonic generation of semiconductors is addressed by using the Wannier gauge. One of the main problems in the time evolution of the Semiconductor Bloch equations resides in the fact that the dipole couplings between different bands can diverge and have a random phase along the reciprocal space and this leads to numerical instability. To address this problem, we propose the use of the Maximally Localized Wannier functions that provide a framework to map ab-initio calculations to an effective tight-binding Hamiltonian with great accuracy. We show that working in the Wannier gauge, the basis set in which the Bloch functions are constructed directly from the Wannier functions, the dipole couplings become smooth along the reciprocal space thus avoiding the problem of random phases. High harmonic generation spectrum is computed for a 2D monolayer of hBN as a numerical demonstration

    CP odd anomalous interactions of Higgs boson in its production at Photon Colliders

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    We discuss the potentialities of the study of CP-odd interactions of the Higgs boson with photons via its production at gamma-gamma and e-gamma colliders. Our treatment of H-gamma-gamma and H-Z-gamma anomalous interactions includes a set of parameters, whose impact on physical observables has not been considered before. We focus on two reactions - gamma+gamma-->H and e+gamma-->eH - and introduce the polarization and/or azimuthal asymmetries that are particularly sensitive to specific features of anomalies. We discuss the ways of disentangling effects of physically different parameters of anomalies and estimate what magnitude of CP violating phenomena can be seen in these experiments.Comment: 17 pages, 9 figs; some modifications in the results presentation; version to be published in Eur.Phys.J.

    Inflation from Supersymmetric Quantum Cosmology

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    We derive a special scalar field potential using the anisotropic Bianchi type I cosmological model from canonical quantum cosmology under determined conditions in the evolution to anisotropic variables β±\beta_\pm. In the process, we obtain a family of potentials that has been introduced by hand in the literature to explain cosmological data. Considering supersymmetric quantum cosmology, this family is scanned, fixing the exponential potential as more viable in the inflation scenario V(ϕ)=V0e3ϕ\rm V (\phi) = V_0 \,e^{-\sqrt{3}\phi}.Comment: 14 pages, latex2e, To appear in Phys. Rev.
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