452 research outputs found
-term as the origin of baryon and lepton number asymmetry
We study a possibility of combining an origin of the -term and the
baryon and lepton number asymmetry. If we assume that the -term is
generated through a flat direction of a singlet scalar field, the coherent
oscillation of this condensate around its potential minimum can store the
global U(1) charge asymmetry. The decay of this condensate can distribute this
asymmetry into the lepton and baryon number asymmetry as far as its decay
occurs at an appropriate temperature. We examine the compatibility between this
scenario and the small neutrino mass generation based on both the ordinary
seesaw mechanism and the bilinear R-parity violating terms.Comment: 22 pages, published versio
Mass bound of the lightest neutral Higgs scalar in the extra U(1) models
The upper mass bound of the lightest neutral Higgs scalar is studied in the
problem solvable extra U(1) models by using the analysis of the
renormalization group equations. In order to restrict the parameter space we
take account of a condition of the radiative symmetry breaking and some
phenomenological constraints. We compare the bound obtained based on this
restricted parameter space with the one of the next to the minimal
supersymmetric standard model (NMSSM). Features of the scalar potential and
renormalization group equations of the Yukawa couplings among Higgs chiral
supermultiplets are rather different between them. They can reflect in this
bound.Comment: 22 pages, latex, 11 eps-figure
The Higgs Sector in a Extension of the MSSM
We consider the Higgs sector in an extension of the MSSM with extra SM
singlets, involving an extra gauge symmetry, in which the
domain-wall problem is avoided and the effective parameter is decoupled
from the new gauge boson mass. The model involves a rich Higgs
structure very different from that of the MSSM. In particular, there are large
mixings between Higgs doublets and the SM singlets, significantly affecting the
Higgs spectrum, production cross sections, decay modes, existing exclusion
limits, and allowed parameter range. Scalars considerably lighter than the LEP2
bound (114 GeV) are allowed, and the range is both allowed
and theoretically favored. Phenomenologically, we concentrate our study on the
lighter (least model-dependent, yet characteristic) Higgs particles with
significant SU(2)-doublet components to their wave functions, for the case of
no explicit CP violation in the Higgs sector. We consider their spectra,
including the dominant radiative corrections to their masses from the top/stop
loop. We computed their production cross sections and reexamine the existing
exclusion limits at LEP2. We outline the searching strategy for some
representative scenarios at a future linear collider. We emphasize that
gaugino, Higgsino, and singlino decay modes are indicative of extended models
and have been given little attention. We present a comprehensive list of model
scenarios in the Appendices.Comment: 49 pages, 17 figure
Suppressing the and neutrino masses by a superconformal force
The idea of Nelson and Strassler to obtain a power law suppression of
parameters by a superconformal force is applied to understand the smallness of
the parameter and neutrino masses in R-parity violating supersymmetric
standard models. We find that the low-energy sector should contain at least
another pair of Higgs doublets, and that a suppression of \lsim O(10^{-13})
for the parameter and neutrino masses can be achieved generically. The
superpotential of the low-energy sector happens to possess an anomaly-free
discrete R-symmetry, either or , which naturally suppresses certain
lepton-flavor violating processes, the neutrinoless double beta decays and also
the electron electric dipole moment. We expect that the escape energy of the
superconformal sector is \lsim O(10) TeV so that this sector will be
observable at LHC. Our models can accommodate to a large mixing among neutrinos
and give the same upper bound of the lightest Higgs mass as the minimal
supersymmetric standard model.Comment: 24 page
Collective Motion and Phase Transitions of Symmetric Camphor Boats
The motion of several self-propelled boats in a narrow channel displays
spontaneous pattern formation and kinetic phase transitions. In contrast with
previous studies on self-propelled particles, this model does not require
stochastic fluctuations and it is experimentally accessible. By varying the
viscosity in the system, it is possible to form either a stationary state,
correlated or uncorrelated oscillations, or unidirectional flow. Here, we
describe and analyze these self organized patterns and their transitions.Comment: 6 pages, 6 figure
Sfermion masses in Nelson-Strassler type of models: SUSY standard models coupled with SCFTs
We study soft SUSY breaking parameters in the Nelson-Strassler type of
models: SUSY standard models coupled with SCFTs. In this type of models, soft
SUSY breaking parameters including sfermion masses can be suppressed around the
decoupling scale of SCFTs. We clarify the condition to derive exponential
suppression of sfermion masses within the framework of pure SCFTs. Such
behavior is favorable for degeneracy of sfermion masses. However, the realistic
sfermion masses are not quite degenerate due to the gauge couplings and the
gaugino masses in the SM sector. We show the sfermion mass spectrum obtained in
such models. The aspect of suppression for the soft SUSY breaking parameters is
also demonstrated in an explicit model. We also give a mechanism generating the
-term of the Electro-Weak scale by a singlet field coupled with the SCFT.Comment: 28 pages, 8 figures, LaTeX file; corrected typos and references adde
The Quiet-Sun Photosphere and Chromosphere
The overall structure and the fine structure of the solar photosphere outside
active regions are largely understood, except possibly important roles of a
turbulent near-surface dynamo at its bottom, internal gravity waves at its top,
and small-scale vorticity. Classical 1D static radiation-escape modelling has
been replaced by 3D time-dependent MHD simulations that come closer to reality.
The solar chromosphere, in contrast, remains ill-understood although its
pivotal role in coronal mass and energy loading makes it a principal research
area. Its fine structure defines its overall structure, so that hard-to-observe
and hard-to-model small-scale dynamical processes are the key to understanding.
However, both chromospheric observation and chromospheric simulation presently
mature towards the required sophistication. The open-field features seem of
greater interest than the easier-to-see closed-field features.Comment: Accepted for special issue "Astrophysical Processes on the Sun" of
Phil. Trans. Royal Soc. A, ed. C. Parnell. Note: clicking on the year in a
citation opens the corresponding ADS abstract page in the browse
Acoustic Events in the Solar Atmosphere from Hinode/SOT NFI observations
We investigate the properties of acoustic events (AEs), defined as spatially
concentrated and short duration energy flux, in the quiet sun using
observations of a 2D field of view (FOV) with high spatial and temporal
resolution provided by the Solar Optical Telescope (SOT) onboard
\textit{Hinode}. Line profiles of Fe \textsc{i} 557.6 nm were recorded by the
Narrow band Filter Imager (NFI) on a FOV during 75 min with a
time step of 28.75 s and 0.08 pixel size. Vertical velocities were computed
at three atmospheric levels (80, 130 and 180 km) using the bisector technique
allowing the determination of energy flux in the range 3-10 mHz using two
complementary methods (Hilbert transform and Fourier power spectra). Horizontal
velocities were computed using local correlation tracking (LCT) of continuum
intensities providing divergences.
The net energy flux is upward. In the range 3-10 mHz, a full FOV space and
time averaged flux of 2700 W m (lower layer 80-130 km) and 2000 W
m (upper layer 130-180 km) is concentrated in less than 1% of the solar
surface in the form of narrow (0.3) AE. Their total duration (including rise
and decay) is of the order of s. Inside each AE, the mean flux is W m (lower layer) and W m (upper). Each
event carries an average energy (flux integrated over space and time) of J (lower layer) to J (upper). More than events
could exist permanently on the Sun, with a birth and decay rate of 3500
s. Most events occur in intergranular lanes, downward velocity regions,
and areas of converging motions.Comment: 18 pages, 10 figure
A Statistical Inference Method for Interpreting the CLASP Observations
On 3rd September 2015, the Chromospheric Lyman-Alpha SpectroPolarimeter
(CLASP) successfully measured the linear polarization produced by scattering
processes in the hydrogen Lyman- line of the solar disk radiation,
revealing conspicuous spatial variations in the and signals. Via
the Hanle effect the line-center and amplitudes encode information
on the magnetic field of the chromosphere-corona transition region (TR), but
they are also sensitive to the three-dimensional structure of this corrugated
interface region. With the help of a simple line formation model, here we
propose a statistical inference method for interpreting the Lyman-
line-center polarization observed by CLASP.Comment: Accepted for publication in The Astrophysical Journa
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