888 research outputs found
Next to new minimal standard model
We suggest a minimal extension of the standard model, which can explain
current experimental data of the dark matter, small neutrino masses and baryon
asymmetry of the universe, inflation, and dark energy, and achieve gauge
coupling unification. The gauge coupling unification can explain the charge
quantization, and be realized by introducing six new fields. We investigate the
vacuum stability, coupling perturbativity, and correct dark matter abundance in
this model by use of current experimental data.Comment: 17 pages, 8 figure
Planck scale boundary conditions in the standard model with singlet scalar dark matter
We investigate Planck scale boundary conditions on the Higgs sector of the
standard model with a gauge singlet scalar dark matter. We will find that
vanishing self-coupling and Veltman condition at the Planck scale are realized
with the 126 GeV Higgs mass and top pole mass, 172 GeV
173.5 GeV, where a correct abundance of scalar dark matter is obtained with
mass of 300 GeV 1 TeV. It means that the Higgs
potential is flat at the Planck scale, and this situation can not be realized
in the standard model with the top pole mass.Comment: 12 pages, 4 figures, version accepted for publication in JHE
Very low scale Coleman-Weinberg inflation with non-minimal coupling
We study viable small-field Coleman-Weinberg (CW) inflation models with the
help of non-minimal coupling to gravity. The simplest small-field CW inflation
model (with a low-scale potential minimum) is incompatible with the
cosmological constraint on the scalar spectral index. However, there are
possibilities to make the model realistic. First, we revisit the CW inflation
model supplemented with a linear potential term. We next consider the CW
inflation model with a logarithmic non-minimal coupling and illustrate that the
model can open a new viable parameter space that includes the model with a
linear potential term. We also show parameter spaces where the Hubble scale
during the inflation can be as small as GeV, GeV, GeV,
and GeV for the number of -folds of , and ,
respectively, with other cosmological constraints being satisfied.Comment: 14 pages, 9 figures, published versio
The annual variability in abundance and shell size of pteropods Limacina spp. in the seasonal ice zone of the Southern Ocean
The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc
Gravitational effects on vanishing Higgs potential at the Planck scale
We investigate gravitational effects on the so-called multiple point
criticality principle (MPCP) at the Planck scale. The MPCP requires two
degenerate vacua, whose necessary conditions are expressed by vanishing Higgs
quartic coupling and vanishing its function
. We discuss a case that a specific form of
gravitational corrections are assumed to contribute to functions of
coupling constants although it is accepted that gravitational corrections do
not alter the running of the standard model (SM) couplings. To satisfy the
above two boundary conditions at the Planck scale, we find that the top pole
mass and the Higgs mass should be and , respectively, as well as
include suitable magnitude of gravitational effects (a coefficient of
gravitational contribution as ). In this case, however, since
the Higgs quartic coupling becomes negative below the Planck scale,
two vacua are not degenerate. We find that with
is required by the realization of the MPCP.
Therefore, the MPCP at the Planck scale cannot be realized in the SM and also
the SM with gravity since is experimentally
ruled out.Comment: 12 pages, 4 figures, version accepted for publication in PRD: typo
corrected, references adde
Accurate renormalization group analyses in neutrino sector
We investigate accurate renormalization group analyses in neutrino sector
between -oscillation and seesaw energy scales. We consider decoupling
effects of top quark and Higgs boson on the renormalization group equations of
light neutrino mass matrix. Since the decoupling effects are given in the
standard model scale and independent of high energy physics, our method can
basically apply to any models beyond the standard model. We find that the
decoupling effects of Higgs boson are negligible, while those of top quark are
not. Particularly, the decoupling effects of top quark affect neutrino mass
eigenvalues, which are important for analyzing predictions such as mass squared
differences and neutrinoless double beta decay in an underlying theory existing
at high energy scale.Comment: 20 pages, 21 figures, version accepted for publication in NPB. Typos
and all figures in Sec.3 corrected, references added, new subsection
(Sec.2.2) adde
Generation of Alfven Waves by Magnetic Reconnection
In this paper, results of 2.5-dimensional magnetohydrodynamical simulations
are reported for the magnetic reconnection of non-perfectly antiparallel
magnetic fields. The magnetic field has a component perpendicular to the
computational plane, that is, guide field. The angle theta between magnetic
field lines in two half regions is a key parameter in our simulations whereas
the initial distribution of the plasma is assumed to be simple; density and
pressure are uniform except for the current sheet region. Alfven waves are
generated at the reconnection point and propagate along the reconnected field
line. The energy fluxes of the Alfven waves and magneto-acoustic waves (slow
mode and fast mode) generated by the magnetic reconnection are measured. Each
flux shows the similar time evolution independent of theta. The percentage of
the energies (time integral of energy fluxes) carried by the Alfven waves and
magneto-acoustic waves to the released magnetic energy are calculated. The
Alfven waves carry 38.9%, 36.0%, and 29.5% of the released magnetic energy at
the maximum (theta=80^\circ) in the case of beta=0.1, 1, and 20 respectively,
where beta is the plasma beta (the ratio of gas pressure to magnetic pressure).
The magneto-acoustic waves carry 16.2% (theta=70^\circ), 25.9%
(theta=60^\circ), and 75.0% (theta=180^\circ) of the energy at the maximum.
Implications of these results for solar coronal heating and acceleration of
high-speed solar wind are discussed.Comment: Accepted for publication in PASJ. 24 pages, 11 figure
Application of menthol as an anesthetizer for body size measurements and morphological obserbation of the genus Clione (Pteropoda: Gymnosomata)
The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc
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