20,775 research outputs found

    A Hardy's Uncertainty Principle Lemma in Weak Commutation Relations of Heisenberg-Lie Algebra

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    In this article we consider linear operators satisfying a generalized commutation relation of a type of the Heisenberg-Lie algebra. It is proven that a generalized inequality of the Hardy's uncertainty principle lemma follows. Its applications to time operators and abstract Dirac operators are also investigated

    Comments on N = 2 supersymmetric sigma models in projective superspace

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    For the most general off-shell N = 2 supersymmetric sigma model in projective superspace, we elaborate on its formulation in terms of N = 1 chiral superfields. A universal (model-independent) expression is obtained for the holomorphic symplectic two-form, which determines the second supersymmetry transformation. This two-form is associated with the two complex structures of the hyperkahler target space, which are complimentary to the one used to realize the target space as a Kahler manifold.Comment: 7 pages; V2: reference [18] correcte

    Distinguished self-adjoint extensions of Dirac operators via Hardy-Dirac inequalities

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    We prove some Hardy-Dirac inequalities with two different weights including measure valued and Coulombic ones. Those inequalities are used to construct distinguished self-adjoint extensions of Dirac operators for a class of diagonal potentials related to the weights in the above mentioned inequalities.Comment: 16 page

    The minimal B-L model naturally realized at TeV scale

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    In a previous paper, we have proposed the minimal B-L extended standard model as a phenomenologically viable model that realizes the Coleman-Weinberg-type breaking of the electroweak symmetry. Assuming the classical conformal invariance and stability up to the Planck scale, we will show in this paper that the model naturally predicts TeV scale B-L breaking as well as a light standard-model singlet Higgs boson and light right-handed neutrinos around the same energy scale. We also study phenomenology and detectability of the model at the Large Hadron Collider (LHC) and the International Linear Collider (ILC).Comment: 24pages, 8figure

    Effects of unparticle on top spin correlation at the Large Hadron Collider

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    We study effects of the scale invariant hidden sector, unparticle, proposed by Georgi, on top spin correlation at the Large Hadron Collider. Assuming no flavor changing interaction between the unparticles and the Standard Model particles, there arises the top-antitop quark pair production process through virtual unparticle exchanges in the s-channel in addition to the Standard Model processes. In particular, we consider contributions of scalar and vector unparticles and find that these make sizable deviations of the top spin correlation from the Standard Model one.Comment: 29 pages, 1 table, 12 figures, 2 figures added, typos in captions corrected, version accepted for publication in PR

    Quantum Hall effects of graphene with multi orbitals: Topological numbers, Boltzmann conductance and Semi-classical quantization

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    Hall conductance σxy\sigma_{xy} as the Chern numbers of the Berry connection in the magnetic Brillouin zone is calculated for a realistic multi band tight-band model of graphene with non-orthogonal basis. It is confirmed that the envelope of σxy\sigma_{xy} coincides with a semi-classical result when magnetic field is sufficiently small. The Hall resistivity ρxy\rho_{xy} from the weak-field Boltzmann theory also explains the overall behaviour of the σxy\sigma_{xy} if the Fermi surface is composed of a single energy band. The plateaux of σxy\sigma_{xy} are explained from semi-classical quantization and necessary modification is proposed for the Dirac fermion regimes.Comment: 5pages, 3figure

    Matrix representation of the time operator

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    In quantum mechanics the time operator Θ\Theta satisfies the commutation relation [Θ,H]=i[\Theta,H]=i, and thus it may be thought of as being canonically conjugate to the Hamiltonian HH. The time operator associated with a given Hamiltonian HH is not unique because one can replace Θ\Theta by Θ+Θhom\Theta+ \Theta_{\rm hom}, where Θhom\Theta_{\rm hom} satisfies the homogeneous condition [Θhom,H]=0[\Theta_{\rm hom},H]=0. To study this nonuniqueness the matrix elements of Θ\Theta for the harmonic-oscillator Hamiltonian are calculated in the eigenstate basis. This calculation requires the summation of divergent series, and the summation is accomplished by using zeta-summation techniques. It is shown that by including appropriate homogeneous contributions, the matrix elements of Θ\Theta simplify dramatically. However, it is still not clear whether there is an optimally simple representation of the time operator.Comment: 13 pages, 3 figure

    Meta-stable Vacuum in Spontaneously Broken N=2 Supersymmetric Gauge Theory

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    We consider an N=2 supersymmetric SU(2) \times U(1) gauge theory with N_f=2 massless flavors and a Fayet-Iliopoulos (FI) term. In the presence of the FI term, supersymmetry is spontaneously broken at tree level (on the Coulomb branch), leaving a pseudo-flat direction in the classical potential. This vacuum degeneracy is removed once quantum corrections are taken into account. Due to the SU(2) gauge dynamics, the effective potential exhibits a local minimum at the dyon point, where not only supersymmetry but also U(1)_R symmetry is broken, while a supersymmetric vacuum would be realized toward infinity with the runaway behavior of the potential. This local minimum is found to be parametrically long-lived. Interestingly, from a phenomenological point of view, in this meta-stable vacuum the massive hypermultiplets inherent in the theory play the role of the messenger fields in the gauge mediation scenario, when the Standard Model gauge group is embedded into their flavor symmetry.Comment: 27 pages, 11 figures, journal reference added, minor modifications in the tex
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