906 research outputs found
Cosmologically safe QCD axion as a present from extra dimension
We propose a QCD axion model where the origin of PQ symmetry and suppression
of axion isocurvature perturbations are explained by introducing an extra
dimension. Each extra quark-antiquark pair lives on branes separately to
suppress PQ breaking operators. The size of the extra dimension changes after
inflation due to an interaction between inflaton and a bulk scalar field, which
implies that the PQ symmetry can be drastically broken during inflation to
suppress undesirable axion isocurvature fluctuations.Comment: 6 page
Diphoton Excess as a Hidden Monopole
We provide a theory with a monopole of a strongly-interacting hidden U(1)
gauge symmetry that can explain the 750-GeV diphoton excess reported by ATLAS
and CMS. The excess results from the resonance of monopole, which is produced
via gluon fusion and decays into two photons. In the low energy, there are only
mesons and a monopole in our model because any baryons cannot be gauge
invariant in terms of strongly interacting Abelian symmetry. This is
advantageous of our model because there is no unwanted relics around the BBN
epoch.Comment: 6 pages, 1 figur
Unification of the Standard Model and Dark Matter Sectors in [SU(5)U(1)]
A simple model of dark matter contains a light Dirac field charged under a
hidden U(1) gauge symmetry. When a chiral matter content in a strong dynamics
satisfies the t'Hooft anomaly matching condition, a massless baryon is a
natural candidate of the light Dirac field. One realization is the same matter
content as the standard SU(5)U(1) grand unified theory. We
propose a chiral [SU(5)U(1)] gauge theory as a unified model of the
SM and DM sectors. The low-energy dynamics, which was recently studied, is
governed by the hidden U(1) gauge interaction and the third-family
U(1) gauge interaction. This model can realize self-interacting
dark matter and alleviate the small-scale crisis of collisionless cold dark
matter in the cosmological structure formation. The model can also address the
semi-leptonic -decay anomaly reported by the LHCb experiment.Comment: 15 pages, 2 figure
The Viscoelastic Properties of Wood Used for Musical Instruments II
この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。In order to make clear the relation between the acoustic properties and the fine structures of wood, the present paper deals with the dynamic mechanical and dielectric properties in relation to the angle of micellar orientation and the degree of crystallinity estimated by X-ray measurements of wood using for the musical instruments (Sitka spruce) and other few wood species (Hinoki, Sugi and Hoonoki). The dynamic elastic modulus, loss modulus, dielectric constant and loss factor for Sitka spruce were large in magnitude for its specific gravity compared with the other species. The mean angle of micellar orientation and the half width in the distribution function of spiral angle for Sitka spruce were the smallest among the coniferous wood species used. The crystallinity indexes calculated from transmission method for Sitka spruce and Hinoki were smaller than those for Sugi and Hoonoki. From these results, it may be concluded that the principal cause which the dynamic elastic and loss modulus for Sitka spruce are large in magnitude for its density is due to its small angle of micellar orientation and/or its uniformity in the gross structures
Experiment on Unsymmetrical Subharmonic Oscillations in a Symmetrical Three-Phase Circuit
This paper presents several results of experiments on the generation of 1/3-subharmonic oscillations in a nonlinear symmetrical three-phase circuit. Particular attention is paid to the generation of unsymmetrical modes. Furthermore we describe a switching phase controller essential to the generation of the subharmonic oscillations in the experimental circuits
Representations of Inverse Functions by the Integral Transform with the Sign Kernel
Mathematics Subject Classification: Primary 30C40In this paper we give practical and numerical representations of inverse
functions by using the integral transform with the sign kernel, and show
corresponding numerical experiments by using computers. We derive a very
simple formula from a general idea for the representation of the inverse
functions, based on the theory of reproducing kernels
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