Rare decay B→Xsl+l−B\to X_sl^+l^- in a CP spontaneously broken two Higgs doublet model

The Higgs boson mass spectrum and couplings of neutral Higgs bosons to fermions are worked out i n a CP spontaneously broken two Higgs doublet model in the large tan$\beta$ case. The differential branching ratio, forward-backward asymmetry, CP asymmetry and lepton polarization for $B\to X_s l^+ l^-$ are computed. It is shown that effects of neutral Higgs bosons are quite significant when $\tan\beta$ is large. Especially, the CP violating normal polarization $P_N$ can be as large as several percents.Comment: 27 pages, text updated, new numerical results include

Scales, Couplings Revisited and Low Energy Phenomenology in M-theory on S1/Z2S^1/Z_2

We revisit the eleven dimension Planck scale, the physical scale of the eleventh dimension, the physical scale of Calabi-Yau manifold and coupling in hidden sector in M-theory on $S^1/Z_2$. And we discuss the reasonable bound on them. Considering F-term of dilaton and moduli SUSY breaking and choosing two repersentative points which correspond to scalar quasi-massless scenario and dilaton dominant SUSY breaking scenario respectively, we analyze experimental constraints to the parameter space. The sparticle spectrum and some phenomenological predictions are also given.Comment: 35 pages and 8 eps files. One error on fig1b is correcte

Fluid-structure interaction modeling on a 3D ray-strengthened caudal fin

In this paper, we present a numerical model capable of solving the fluid-structure interaction problems involved in the dynamics of skeleton-reinforced fish fins. In this model, the fluid dynamics is simulated by solving the Navier-Stokes equations using a finite-volume method based on an overset, multi-block structured grid system. The bony rays embedded in the fin are modeled as nonlinear Euler-Bernoulli beams. To demonstrate the capability of this model, we numerically investigate the effect of various ray stiffness distributions on the deformation and propulsion performance of a 3D caudal fin. Our numerical results show that with specific ray stiffness distributions, certain caudal fin deformation patterns observed in real fish (e.g. the cupping deformation) can be reproduced through passive structural deformations. Among the four different stiffness distributions (uniform, cupping, W-shape and heterocercal) considered here, we find that the cupping distribution requires the least power expenditure. The uniform distribution, on the other hand, performs the best in terms of thrust generation and efficiency. The uniform stiffness distribution, per se, also leads to 'cupping' deformation patterns with relatively smaller phase differences between various rays. The present model paves the way for future work on dynamics of skeleton-reinforced membranes

Generalization of Friedberg-Lee Symmetry

We study the possible origin of Friedberg-Lee symmetry. First, we propose the generalized Friedberg-Lee symmetry in the potential by including the scalar fields in the field transformations, which can be broken down to the FL symmetry spontaneously. We show that the generalized Friedberg-Lee symmetry allows a typical form of Yukawa couplings, and the realistic neutrino masses and mixings can be generated via see-saw mechanism. If the right-handed neutrinos transform non-trivially under the generalized Friedberg-Lee symmetry, we can have the testable TeV scale see-saw mechanism. Second, we present two models with the $SO(3)\times U(1)$ global flavour symmetry in the lepton sector. After the flavour symmetry breaking, we can obtain the charged lepton masses, and explain the neutrino masses and mixings via see-saw mechanism. Interestingly, the complete neutrino mass matrices are similar to those of the above models with generalized Friedberg-Lee symmetry. So the Friedberg-Lee symmetry is the residual symmetry in the neutrino mass matrix after the $SO(3)\times U(1)$ flavour symmetry breaking.Comment: 16 pages, no figure, version published in PR

Effect of exogenous gibberellin on endogenous hormone and ginkgolide content in Ginkgo leaves

Ginkgolide is one of the important secondary metabolites of Ginkgo biloba. The synthesis of plant secondary metabolites is influenced by exogenous phytohormones. In this study, ten-year-old ginkgo grafted seedlings were used as the test material, and the effects of 0, 2, 4, 6, 8, and 10 mmol L–1 gibberellin (GA3) on endogenous indole acetic acid (IAA), abscisic acid (ABA), GA3, and ginkgolide contents in ginkgo leaves were investigated. Results showed that exogenous GA3 treatment inhibited endogenous GA3, changed the contents of endogenous IAA and ABA in ginkgo leaves, and affected the accumulation of secondary metabolite ginkgolides. Among the given concentrations, the 4 mmol L–1 GA3 treatment could remarkably increase ginkgolide content. We found that the best harvesting period of ginkgo leaves were in late August and late September, in which the content of ginkgolides was the highest

A New Imperative for Detracking Schools. A Book Review of \u3cem\u3eOn the Same Track:How Schools Can Join the Twenty-First-Century Struggle Against Resegregation\u3c/em\u3e

In her 2014 book, On the Same Track: How Schools Can Join the Twenty-First-Century Struggle Against Resegregation, Burris builds upon the compelling case made for detracking put forth by Oakes and others in the 1970s and ’80s. Today, decades after the pioneers in detracking schools, Burris revisits the tracking practices still prevalent in America’s public schools through the lenses of those who are in the racial or ethnic minority and who are poor and at a time when school accountability often drives school practice and school choice to additional layers of sorting

SU(3)FSU(3)_F Meson Mass Formula from Random Phase Approximation

We present a $SU(3)_F$ meson mass formula from random phase approximation (RPA). Both the mesons of ground-state pseudoscalar octet and the ground-state vector octet are described quite well in this mass formula. We also estimate the current and constituent quark masses from the na\"{\i}ve quark model with the PCAC relation