1,046 research outputs found
Neutrino mass from higher than d=5 effective operators in SUSY, and its test at the LHC
We discuss neutrino masses from higher than d=5 effective operators in a
supersymmetric framework, where we explicitly demonstrate which operators could
be the leading contribution to neutrino mass in the MSSM and NMSSM. As an
example, we focus on the d=7 operator L L H_u H_u H_d H_u, for which we
systematically derive all tree-level decompositions. We argue that many of
these lead to a linear or inverse see-saw scenario with two extra neutral
fermions, where the lepton number violating term is naturally suppressed by a
heavy mass scale when the extra mediators are integrated out. We choose one
example, for which we discuss possible implementations of the neutrino flavor
structure. In addition, we show that the heavy mediators, in this case SU(2)
doublet fermions, may indeed be observable at the LHC, since they can be
produced by Drell-Yan processes and lead to displaced vertices when they decay.
However, the direct observation of lepton number violating processes is on the
edge at LHC.Comment: 24 pages, 5 figures, 6 table
DECOLORIZATION OF ORANGE 16 BY BACTERIA
Joint Research on Environmental Science and Technology for the Eart
Phase effects from the general neutrino Yukawa matrix on lepton flavor violation
We examine contributions from Majorana phases to lepton flavor violating
processes in the framework of the minimal supersymmetric standard model with
heavy right-handed neutrinos. All phases in the complex neutrino Yukawa matrix
are taken into account in our study. We find that in the scenario with
universal soft-breaking terms sizable phase effects can appear on the lepton
flavor violating processes such as , , and
. In particular, the branching ratio of
can be considerably enhanced due to the Majorana phases, so that it can be much
greater than that of .Comment: 14 pages, 4 eps figures, revtex
Enhancement of lepton flavor violation in a model with bi-maximal mixing at the grand unification scale
We study phenomenological predictions in the scenario with the
quasi-degenerate relation among neutrino Dirac masses, m_D1 simeq m_D2 < m_D3,
assuming the bi-maximal mixing at the grand unification scale in supersymmetric
standard models with right-handed neutrinos. A sufficient lepton number
asymmetry can be produced for successful leptogenesis. The lepton flavor
violating process mu to e gamma can be enhanced due to the Majorana phase, so
that it can be detectable at forthcoming experiments. The processes tau to e
gamma and tau to mu gamma are suppressed because of the structure of neutrino
Dirac masses, and their branching ratios are smaller than that of mu to e
gamma.Comment: 15 pages, 5 figure
Characterization and Improvement of the Image Quality of the Data Taken with the Infrared Camera (IRC) Mid-Infrared Channels onboard AKARI
Mid-infrared images frequently suffer artifacts and extended point spread
functions (PSFs). We investigate the characteristics of the artifacts and the
PSFs in images obtained with the Infrared Camera (IRC) onboard AKARI at four
mid-infrared bands of the S7 (7{\mu}m), S11 (11{\mu}m), L15 (15{\mu}m), and L24
(24 {\mu}m). Removal of the artifacts significantly improves the reliability of
the ref- erence data for flat-fielding at the L15 and L24 bands. A set of
models of the IRC PSFs is also constructed from on-orbit data. These PSFs have
extended components that come from diffraction and scattering within the
detector arrays. We estimate the aperture correction factors for point sources
and the surface brightness correction factors for diffuse sources. We conclude
that the surface brightness correction factors range from 0.95 to 0.8, taking
account of the extended component of the PSFs. To correct for the extended PSF
effects for the study of faint structures, we also develop an image
reconstruction method, which consists of the deconvolution with the PSF and the
convolution with an appropriate Gaussian. The appropriate removal of the
artifacts, improved flat-fielding, and image reconstruction with the extended
PSFs enable us to investigate de- tailed structures of extended sources in IRC
mid-infrared images.Comment: 35 pages, 15 figures, accepted for publication in PAS
Light neutralino in the MSSM: An update with the latest LHC results
We discuss the scenario of light neutralino dark matter in the minimal
supersymmetric standard model, which is motivated by the results of some of the
direct detection experiments --- DAMA, CoGENT, and CRESST. We update our
previous analysis with the latest results of the LHC. We show that new LHC
constraints disfavour the parameter region that can reproduce the results of
DAMA and CoGENT.Comment: 4 pages, 4 figures, to appear in the conference proceedings of TAUP
2011, Munich Germany, 5-9 September 201
Classification of minimal actions of a compact Kac algebra with amenable dual
We show the uniqueness of minimal actions of a compact Kac algebra with
amenable dual on the AFD factor of type II. This particularly implies the
uniqueness of minimal actions of a compact group. Our main tools are a Rohlin
type theorem, the 2-cohomology vanishing theorem, and the Evans-Kishimoto type
intertwining argument.Comment: 68 pages, Introduction rewritten; minor correction
Effects of the and of other processes on the mixing hierarchies in the four-generation model
We analyze in the four-generation model the first measurement of the
branching ratio of rare kaon decay , along with the
other processes of mass difference , CP-violating
parameter mixing, mixing,
, and the upper bound values of mixing
and , and try to search for mixing of the fourth
generation in the hierarchical mixing scheme of the Wolfenstein
parametrization. Using the results for the mixing of the fourth generation, we
discuss predictions of the mixing () and the
branching ratio of directly CP-violating decay process
, and the effects on the CP asymmetry in neutral B
meson decays and the unitarity triangle.Comment: 29 pages written in LaTex. 6 figures(drawn on LaTeX). Revised from
" in the four-generation model" of the same
Authors(TOKUSHIMA 99-1, January 1999). A minor chang
Selective activation of primary afferent fibers evaluated by sine-wave electrical stimulation
Transcutaneous sine-wave stimuli at frequencies of 2000, 250 and 5 Hz (Neurometer) are thought to selectively activate Aβ, Aδ and C afferent fibers, respectively. However, there are few reports to test the selectivity of these stimuli at the cellular level. In the present study, we analyzed action potentials (APs) generated by sine-wave stimuli applied to the dorsal root in acutely isolated rat dorsal root ganglion (DRG) preparations using intracellular recordings. We also measured excitatory synaptic responses evoked by transcutaneous stimuli in substantia gelatinosa (SG) neurons of the spinal dorsal horn, which receive inputs predominantly from C and Aδ fibers, using in vivo patch-clamp recordings. In behavioral studies, escape or vocalization behavior of rats was observed with both 250 and 5 Hz stimuli at intensity of ~0.8 mA (T5/ T250), whereas with 2000 Hz stimulation, much higher intensity (2.14 mA, T2000) was required. In DRG neurons, APs were generated at T5/T250 by 2000 Hz stimulation in Aβ, by 250 Hz stimulation both in Aβ and Aδ, and by 5 Hz stimulation in all three classes of DRG neurons. However, the AP frequencies elicited in Aβ and Aδ by 5 Hz stimulation were much less than those reported previously in physiological condition. With in vivo experiments large amplitude of EPSCs in SG neurons were elicited by 250 and 5 Hz stimuli at T5/ T250. These results suggest that 2000 Hz stimulation excites selectively Aβ fibers and 5 Hz stimulation activates noxious transmission mediated mainly through C fibers. Although 250 Hz stimulation activates both Aδ and Aβ fibers, tactile sensation would not be perceived when painful sensation is produced at the same time. Therefore, 250 Hz was effective stimulus frequency for activation of Aδ fibers initiating noxious sensation. Thus, the transcutaneous sine-wave stimulation can be applied to evaluate functional changes of sensory transmission by comparing thresholds with the three stimulus frequencies
Temporospatial sonic hedgehog signalling is essential for neural crest-dependent patterning of the intrinsic tongue musculature
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