1,584 research outputs found
Renormalization Group Effects on the Mass Relation Predicted by the Standard Model with Generalized Covariant Derivatives
Renormalization group analysis is made on the relation for masses of the top quark and the Higgs boson, which is
predicted by the standard model based on generalized covariant derivatives with
gauge and Higgs fields. This relation is a low energy manifestation of a tree
level constraint which holds among the quartic Higgs self-coupling constant and
the Yukawa coupling constants at a certain high energy scale . With the
renormalization group equation at one-loop level, the evolution of the
constraint is calculated from down to the low energy region around the
observed top quark mass. The result of analysis shows that the Higgs boson mass
is in for a wide range of the
energy scale and it approaches to 177 GeV ()
for large values of .Comment: 13 pages, LaTeX, no figure
Tri-bimaximal Mixing and Cabibbo Angle in S4 Flavor Model with SUSY
We present a flavor model of quarks and leptons with the non-Abelian discrete
symmetry in the framework of the SU(5) SUSY GUT. Three generations of
-plets in SU(5) are assigned to of while the first and
second generations of 10-plets in SU(5) are assigned to of , and
the third generation of 10-plet is assigned to of . Right-handed
neutrinos are also assigned to for the first and second generations
and for the third generation. We predict the Cabibbo angle as well
as the tri-bimaximal mixing of neutrino flavors. We also predict the
non-vanishing of the neutrino flavor mixing due to higher dimensional
mass operators. Our predicted CKM mixing angles and the CP violation are
consistent with experimental values. We also study SUSY breaking terms in the
slepton sector. Our model leads to smaller values of flavor changing neutral
currents than the present experimental bounds.Comment: 32 pages, 4 figures, some references are added, with minor
modificatio
Irregular conformal blocks, with an application to the fifth and fourth Painlev\'e equations
We develop the theory of irregular conformal blocks of the Virasoro algebra.
In previous studies, expansions of irregular conformal blocks at regular
singular points were obtained as degeneration limits of regular conformal
blocks; however, such expansions at irregular singular points were not clearly
understood. This is because precise definitions of irregular vertex operators
had not been provided previously. In this paper, we present precise definitions
of irregular vertex operators of two types and we prove that one of our vertex
operators exists uniquely. Then, we define irregular conformal blocks with at
most two irregular singular points as expectation values of given irregular
vertex operators. Our definitions provide an understanding of expansions of
irregular conformal blocks and enable us to obtain expansions at irregular
singular points.
As an application, we propose conjectural formulas of series expansions of
the tau functions of the fifth and fourth Painlev\'e equations, using
expansions of irregular conformal blocks at an irregular singular point.Comment: 26 page
Asperity characteristics of the Olami-Feder-Christensen model of earthquakes
Properties of the Olami-Feder-Christensen (OFC) model of earthquakes are
studied by numerical simulations. The previous study indicated that the model
exhibits ``asperity''-like phenomena, {\it i.e.}, the same region ruptures many
times near periodically [T.Kotani {\it et al}, Phys. Rev. E {\bf 77}, 010102
(2008)]. Such periodic or characteristic features apparently coexist with
power-law-like critical features, {\it e.g.}, the Gutenberg-Richter law
observed in the size distribution. In order to clarify the origin and the
nature of the asperity-like phenomena, we investigate here the properties of
the OFC model with emphasis on its stress distribution. It is found that the
asperity formation is accompanied by self-organization of the highly
concentrated stress state. Such stress organization naturally provides the
mechanism underlying our observation that a series of asperity events repeat
with a common epicenter site and with a common period solely determined by the
transmission parameter of the model. Asperity events tend to cluster both in
time and in space
Universal Seesaw Mechanism with Universal Strength for Yukawa Couplings
Hypotheses of the universal seesaw mechanism and the {\it universal strength
for Yukawa couplings} are applied to explain one possible origin of
quasi-democratic mass matrices of a special type in a left-right symmetric
model with the gauge group .
Two kinds of Higgs doublets are postulated to mediate scalar interactions
between the -th generation of light fermion doublets and the -th
generation of heavy fermion singlets with relative Yukawa coupling constants of
the exponential form , where are real phase
constants. The lowest seesaw approximation results effectively in self-adjoint
mass matrices which are quasi-democratic and have the same diagonal elements. A
set of values for the parameters is found which reproduces the
present experimental data for the absolute values of the CKM matrix elements,
the Jarlskog parameter and the Wolfenstein parameters.Comment: Latex, 16 pages, no figure
Resonant growth of stellar oscillations by incident gravitational waves
Stellar oscillation under the combined influences of incident gravitational
wave and radiation loss is studied in a simple toy model. The star is
approximated as a uniform density ellipsoid in the Newtonian gravity including
radiation damping through quadrupole formula. The time evolution of the
oscillation is significantly controlled by the incident wave amplitude ,
frequency and damping time . If a combination
exceeds a threshold value, which depends on the resonance mode, the resonant
growth is realized.Comment: 11 pages, 6 figures, Accepted for the publication in Classical and
Quantum Gravit
Systematic Errors in the Hubble Constant Measurement from the Sunyaev-Zel'dovich effect
The Hubble constant estimated from the combined analysis of the
Sunyaev-Zel'dovich effect and X-ray observations of galaxy clusters is
systematically lower than those from other methods by 10-15 percent. We examine
the origin of the systematic underestimate using an analytic model of the
intracluster medium (ICM), and compare the prediction with idealistic triaxial
models and with clusters extracted from cosmological hydrodynamical
simulations. We identify three important sources for the systematic errors;
density and temperature inhomogeneities in the ICM, departures from
isothermality, and asphericity. In particular, the combination of the first two
leads to the systematic underestimate of the ICM spectroscopic temperature
relative to its emission-weighed one. We find that these three systematics well
reproduce both the observed bias and the intrinsic dispersions of the Hubble
constant estimated from the Sunyaev-Zel'dovich effect.Comment: 26 pages, 7 figures, accepted for publication in ApJ, Minor change
Bending strength of multi‐layered alumina with controlled residual stress
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