Radiative symmetry breaking and Higgs mass bound in the NMSSM

We study the upper mass bound of the lightest neutral Higgs scalar in the NMSSM using the RGE analysis. We require the successful occurence of the electroweak radiative symmetry breaking to restrict the parameter space. As a result the upper mass bound $m_{h^0}$ is largely restricted compared with the one estimated without imposing this condition. We point out some features of $m_{h^0}$ related to the initial value of $h_t$ and discuss why the models with more extra matters ${\bf 5}+\bar{\bf 5}$ of SU(5) could bring the larger maximum value of $m_{h^0}$.Comment: 8 pages, latex, 4 eps-figure

S_4 x Z_2 Flavor Symmetry in Supersymmetric Extra U(1) Model

We propose a E_6 inspired supersymmetric model with a non-Abelian discrete flavor symmetry (S_4 group); that is, SU(3)_c x SU(2)_W x U(1)_Y x U(1)_X x S_4 x Z_2. In our scenario, the additional abelian gauge symmetry; U(1)_X, not only solves the mu-problem in the minimal Supersymmetric Standard Model(MSSM), but also requires new exotic fields which play an important role in solving flavor puzzles. If our exotic quarks can be embedded into a S_4 triplet, which corresponds to the number of the generation, one finds that dangerous proton decay can be well-suppressed. Hence, it might be expected that the generation structure for lepton and quark in the SM(Standard Model) can be understood as a new system in order to stabilize the proton in a supersymemtric standard model (SUSY). Moreover, due to the nature of the discrete non-Abelian symmetry itself, Yukawa coupling constants of our model are drastically reduced. In our paper, we show two predictive examples of the models for quark sector and lepton sector, respectively.Comment: 14 pages, 4 tables. Flavon sector and references are added. Sentences are modifie

Mass bound of the lightest neutral Higgs scalar in the extra U(1) models

金沢大学理学部金沢大学大学院自然科学研究科物理学The upper mass bound of the lightest neutral Higgs scalar is studied in the μ 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. ©2000 The American Physical Society

DEM Simulation of Soil Loosening Process Caused by a Vibrating Subsoiler

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): DEM Simulation of Soil Loosening Process Caused by a Vibrating Subsoiler. Manuscript PM 05 010. Vol. IX. November, 2007

Discrete symmetries and models of flavor mixing

Evidences of a discrete symmetry behind the pattern of lepton mixing are analyzed. The program of "symmetry building" is outlined. Generic features and problems of realization of this program in consistent gauge models are formulated. The key issues include the flavor symmetry breaking, connection of mixing and masses, {\it ad hoc} prescription of flavor charges, "missing" representations, existence of new particles, possible accidental character of the TBM mixing. Various ways are considered to extend the leptonic symmetries to the quark sector and to reconcile them with Grand Unification. In this connection the quark-lepton complementarity could be a viable alternative to TBM. Observational consequences of the symmetries and future experimental tests of their existence are discussed.Comment: 14 pages, 5 figures. Talk given at the Symposium "DISCRETE 2010", 6 - 11 December 2010, La Sapienza, Rome, Ital

COMPARISON OF SOLUTION ALGORITHM FOR FLOW AROUND A SQUARE CYLINDER

ABSTRACT Numerical accuracy, numerical stability and calculation time are all important factors in the computational fluid dynamics. In this study, we compare two solution algorithms, the Simplified Marker and Cell (SMAC) method in the MAC-type methods and the Semi-Implicit Method for Pressure-Linked Equation (SIMPLE) algorithm in the SIMPLE-type algorithms, with respect to flow around a square cylinder in constant density and unsteady-state calculations using a staggered grid to investigate the numerical accuracy, the numerical stability and the computational time. For the flow around a square cylinder, the SMAC and SIMPLE solutions are in excellent agreement at the Strouhal number, drag and lift coefficients. However, SMAC is more unstable than SIMLE with a large Courant number. The computational time of the SMAC is shorter than that of the SIMPLE with a small Courant number

TGF-β-driven reduction of cytoglobin leads to oxidative DNA damage in stellate cells during non-alcoholic steatohepatitis

BACKGROUND: Cytoglobin (CYGB) is a respiratory protein that acts as a scavenger of reactive oxygen species. Although CYGB is expressed uniquely in hepatic stellate cells (HSCs) in the liver, the molecular role of CYGB in human HSC activation and human liver disease remains uncharacterised. The aim of this study was to reveal the mechanism by which TGF-β1/SMAD2 pathway regulates human CYGB promoter and the pathophysiological function of CYGB in human non-alcoholic steatohepatitis (NASH). METHODS: Immunohistochemical staining was performed using human NASH biopsy specimens. Molecular and biochemical analysis were performed by western blotting, quantitative PCR, and luciferase and immunoprecipitation assays. Hydroxyl radicals (•OH) and oxidative DNA damage were measured using an •OH-detectable probe and 8-hydroxy-2’-deoxyguanosine (8-OHdG) ELISA. RESULTS: In culture, TGF-β1-pretreated human hepatic stellate cells (HHSteCs) exhibited lowered CYGB levels together with increased NADPH oxidase 4 (NOX4) expression and were primed for H_{2}O_{2}-triggered OH production and 8-OHdG generation. Overexpression of human CYGB in HHSteCs cancelled out those effects of TGF-β1. Electron spin resonance demonstrated direct •OH-scavenging activity of recombinant human CYGB. Mechanistically, pSMAD2 reduced CYGB transcription by recruiting the M1 repressor isoform of SP3 to the human CYGB promoter at nucleotide positions +2–{+}^13 from the transcription start site. The same repression did not occur on the mouse Cygb promoter. TGF-β1/SMAD3 mediated αSMA and collagen expression. Consistent with those observations in cultured HHSteCs, CYGB expression was negligible, but 8-OHdG was abundant, in activated αSMA^{+}pSMAD2^{+}- and αSMA^{+}NOX4^{+}-positive hepatic stellate cells from human NASH patients with advanced fibrosis. CONCLUSIONS: Downregulation of CYGB by the TGF-β1/pSMAD2/SP3-M1 pathway brings about •OH-dependent oxidative DNA damage in activated hepatic stellate cells from human patients with NASH

Bilinear R-parity violation with flavor symmetry

Bilinear R-parity violation (BRPV) provides the simplest intrinsically supersymmetric neutrino mass generation scheme. While neutrino mixing parameters can be probed in high energy accelerators, they are unfortunately not predicted by the theory. Here we propose a model based on the discrete flavor symmetry $A_4$ with a single R-parity violating parameter, leading to (i) correct Cabbibo mixing given by the Gatto-Sartori-Tonin formula, and a successful unification-like b-tau mass relation, and (ii) a correlation between the lepton mixing angles $\theta_{13}$ and $\theta_{23}$ in agreement with recent neutrino oscillation data, as well as a (nearly) massless neutrino, leading to absence of neutrinoless double beta decay.Comment: 16 pages, 3 figures. Extended version, as published in JHE

Effect of operating conditions on fluid flow over a high speed rotary bell-cup atomizer

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Using the volume of fluid (VOF) method, we analyze two-dimensional fluid flow over high-speed rotary bell-cup atomizers. The fluid behavior is analyzed and the liquid film thickness is quantitatively evaluated. The atomizer is flat in shape and has a paint supply hole. The bell rotational speed obtained is 15,000, 25,000, and 35,000 rpm; and the liquid flow rate obtained is 150, 300, 450, and 600 mL/min. The liquid used in this experiment is assumed to be water and the gas is assumed to be air. The results show that the liquid flows through the bell-cup surface toward the edge and forms a liquid film. At the measuring point, the film is initially thick but it then decreases to a practically constant value. The increase in the bell rotational speed causes the film thickness to decrease. Furthermore, the increase in the rotational speed causes the film thickness to become constant, whereas the increase in the liquid flow rate causes the film thickness to increase. These results show that the rotational speed and flow rate strongly affect the thickness of the filmdc201