1,953 research outputs found
Flavor Mass and Mixing and S_3 Symmetry -- An S_3 Invariant Model Reasonable to All --
We assume that weak bases of flavors (u, c)_{L,R}, (d,s)_{L,R}, (e, \mu)
_{L,R}, (\nu_e, \nu_\mu)_{L,R} are the S_3 doublet and t_{L,R}, b_{L,R},
\tau_{L,R}, {\nu_\tau}_{L,R} are the S_3 singlet and further there are S_3
doublet Higgs (H_D^1, H_D^2) and S_3 singlet Higgs H_S. We suggest an S_3
invariant Yukawa interaction, in which masses caused from the interaction of
S_3 singlet flavors and Higgs is very large and masses caused from interactions
of S_3 doublet flavors and Higgs are very small, and the vacuum expectation
value _0 is rather small compared to the _0. In this model,
we can explain the quark sector mass hierarchy, flavor mixing V_{CKM} and
measure of CP violation naturally. The leptonic sector mass hierarchy and
flavor mixing described by V_{MNS} having one-maximal and one-large mixing
character can also be explained naturally with no other symmetry restriction.
In our model, an origin of Cabibbo angle is the ratio \lambda=_0
/_0 and an origin of CP violation is the phase of H_D^1.Comment: 16 page
Mixing among light scalar mesons and L=1 q\bar{q} scalar mesons
Following the re-establishment of the \sigma(600) and the \kappa(900), the
light scalar mesons a_0(980) and f_0(980) together with the \sigma(600) and the
\kappa(900) are considered as the chiral scalar partner of pseudoscalar nonet
in SU(3) chiral symmetry, and the high mass scalar mesons a_0(1450),
K^*_0(1430), f_0(1370) and f_0(1710) turned out to be considered as the L=1
q\bar{q} scalar mesons. We assume that the high mass of the L=1 q\bar{q} scalar
mesons is caused by the mixing with the light scalar mesons. For the structure
of the light scalar mesons, we adopted the qq\bar{q}\bar{q} model in order to
explain the "scalar meson puzzle". The inter-mixing between the light scalar
nonet and the high mass L=1 q\bar{q} nonet and the intra-mixing among each
nonet are analyzed by including the glueball into the high mass scalar nonet.Comment: 16 pages, 5 figure
Effects to Scalar Meson Decays of Strong Mixing between Low and High Mass Scalar Mesons
We analyze the mass spectroscopy of low and high mass scalar mesons and get
the result that the coupling strengths of the mixing between low and high mass
scalar mesons are very strong and the strengths of mixing for scalar
mesons and those of I=0 scalar mesons are almost same. Next, we analyze the
decay widths and decay ratios of these mesons and get the results that the
coupling constants for which represents the coupling of high
mass scalar meson -> two pseudoscalar mesons are almost same as the
coupling for the I=0. On the other hand, the coupling constant for
which represents the low mass scalar meson -> are far
from the coupling constant for I=0. We consider a resolution for this
discrepancy. Coupling constant for glueball -> is smaller than
the coupling . is .Comment: 15 pages, 6 figure
Development of Atmospheric Monitoring System at Akeno Observatory for the Telescope Array Project
We have developed an atmospheric monitoring system for the Telescope Array
experiment at Akeno Observatory. It consists of a Nd:YAG laser with an
alt-azimuth shooting system and a small light receiver. This system is
installed inside an air conditioned weather-proof dome. All parts, including
the dome, laser, shooter, receiver, and optical devices are fully controlled by
a personal computer utilizing the Linux operating system.
It is now operated as a back-scattering LIDAR System. For the Telescope Array
experiment, to estimate energy reliably and to obtain the correct shower
development profile, the light transmittance in the atmosphere needs to be
calibrated with high accuracy.
Based on observational results using this monitoring system, we consider this
LIDAR to be a very powerful technique for Telescope Array experiments. The
details of this system and its atmospheric monitoring technique will be
discussed.Comment: 24 pages, 13 figures(plus 3 gif files), Published in NIM-A Vol.488,
August 200
Neutrino Large Mixing in Universal Yukawa Coupling Model with Small Violation
We have analyzed the possibility that the universal Yukawa coupling
(democratic mass matrix) with small violations of Dirac and Majorana neutrinos
can induce the large mixing of neutrinos through the seesaw mechanism. The
possibility can be achieved by the condition that the violation parameters of
Majorana neutrinos are sufficiently smaller than the violation parameters of
Dirac neutrinos. Allowed regions of the violation parameters producing the
observed neutrino mass hierarchy and large neutrino mixing are not so
restricted at present in contrast to the violation parameters for quark sector.Comment: 14 pages, 4figure
Wide-Area Mapping of 155 Micron Continuum Emission from the Orion Molecular Cloud Complex
We present the results of a wide-area mapping of the far-infrared continuum
emission toward the Orion complex by using a Japanese balloon-borne telescope.
The 155-um continuum emission was detected over a region of 1.5 deg^2 around
the KL nebula with 3' resolution similar to that of the IRAS 100-um map.
Assuming a single-temperature model of the thermal equilibrium dust, maps of
the temperature and the optical depth were derived from the 155 um intensity
and the IRAS 100 um intensity. The derived dust temperature is 5 - 15 K lower
and the derived dust optical thickness were derived from the 155-um intensity
and the IRAS 100-um intensity. The derived dust temperature is 5 - 15 K lower
and the derived dust optical depth is 5 - 300 times larger than those derived
from the IRAS 60 and 100-um intensities due to the significant contribution of
the statistically heated very small grains to the IRAS 60-um intensity. The
optical-thickness distribution shows a filamentary dust ridge that has a 1.5
degrees extent in the north - south direction and well resembles the
Integral-Shaped Filament (ISF) molecular gas distribution. The gas-to-dust
ratio derived from the CO molecular gas distribution along the ISF is in the
range 30 - 200, which may be interpreted as being an effect of CO depletion due
to the photodissociation and/or the freezing on dust grains.Comment: 23 pages, 7 figures, 1 table, to appear in PASJ, Vol. 56, No.
Bi-large Neutrino Mixing and Mass of the Lightest Neutrino from Third Generation Dominance in a Democratic Approach
We show that both small mixing in the quark sector and large mixing in the
lepton sector can be obtained from a simple assumption of universality of
Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading
order. We discuss conditions under which bi-large mixing in the lepton sector
is achieved with a minimal amount of fine-tuning requirements for possible
models. From knowledge of the solar and atmospheric mixing angles we determine
the allowed values of sin \theta_{13}. If embedded into grand unified theories,
the third generation Yukawa coupling unification is a generic feature while
masses of the first two generations of charged fermions depend on small
perturbations. In the neutrino sector, the heavier two neutrinos are model
dependent, while the mass of the lightest neutrino in this approach does not
depend on perturbations in the leading order. The right-handed neutrino mass
scale can be identified with the GUT scale in which case the mass of the
lightest neutrino is given as (m_{top}^2/M_{GUT}) sin^2 \theta_{23} sin^2
\theta_{12} in the limit sin \theta_{13} = 0. Discussing symmetries we make a
connection with hierarchical models and show that the basis independent
characteristic of this scenario is a strong dominance of the third generation
right-handed neutrino, M_1, M_2 < 10^{-4} M_3, M_3 = M_{GUT}.Comment: typos correcte
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