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 $\mu \to e \gamma$, $\tau \to e \gamma$, and $\tau \to \mu \gamma$. In particular, the branching ratio of $\mu \to e \gamma$ can be considerably enhanced due to the Majorana phases, so that it can be much greater than that of $\tau \to \mu \gamma$.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$_1$. 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 K+→π+ννˉK^+\to\pi^+\nu\bar{\nu} 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 $K^+\to\pi^+\nu\bar{nu}$, along with the other processes of $K_L-K_S$ mass difference $\Delta m_K$, CP-violating parameter $\epsilon_K, B_d-\bar{B_d}$ mixing, $B_s-\bar{B_s}$ mixing, $B(K_L\to\mu\bar{\mu})$, and the upper bound values of $D^0-\bar{D^0}$ mixing and $B(K_L\to\pi^0\nu\bar{\nu})$, 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 $D^0-\bar{D^0}$ mixing ($\Delta m_D$) and the branching ratio of directly CP-violating decay process $K_L\to\pi^0\nu\bar{\nu}$, 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 "$K^+\to\pi^+\nu\bar{\nu}$ 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