16,882 research outputs found
Effects of unparticle on top spin correlation at the Large Hadron Collider
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
A Hardy's Uncertainty Principle Lemma in Weak Commutation Relations of Heisenberg-Lie Algebra
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
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
Massive Hyper-Kahler Sigma Models and BPS Domain Walls
With the non-Abelian Hyper-Kahler quotient by U(M) and SU(M) gauge groups, we
give the massive Hyper-Kahler sigma models that are not toric in the N=1
superfield formalism. The U(M) quotient gives N!/[M! (N-M)!] (N is a number of
flavors) discrete vacua that may allow various types of domain walls, whereas
the SU(M) quotient gives no discrete vacua. We derive BPS domain wall solution
in the case of N=2 and M=1 in the U(M) quotient model.Comment: 16 pages, 1 figure, contribution to the Proceedings of the
International Conference on "Symmetry Methods in Physics (SYM-PHYS10)" held
at Yerevan, Armenia, 13-19 Aug. 200
Polar supermultiplets, Hermitian symmetric spaces and hyperkahler metrics
We address the construction of four-dimensional N=2 supersymmetric nonlinear
sigma models on tangent bundles of arbitrary Hermitian symmetric spaces
starting from projective superspace. Using a systematic way of solving the
(infinite number of) auxiliary field equations along with the requirement of
supersymmetry, we are able to derive a closed form for the Lagrangian on the
tangent bundle and to dualize it to give the hyperkahler potential on the
cotangent bundle. As an application, the case of the exceptional symmetric
space E_6/SO(10) \times U(1) is explicitly worked out for the first time.Comment: 17 page
Distinguished self-adjoint extensions of Dirac operators via Hardy-Dirac inequalities
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
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
Quantum Hall effects of graphene with multi orbitals: Topological numbers, Boltzmann conductance and Semi-classical quantization
Hall conductance 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 coincides with a semi-classical result when
magnetic field is sufficiently small.
The Hall resistivity from the weak-field Boltzmann theory also
explains the overall behaviour of the if the Fermi surface is
composed of a single energy band. The plateaux of are explained
from semi-classical quantization and necessary modification is proposed for the
Dirac fermion regimes.Comment: 5pages, 3figure
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