Finding the Leptonic WWWW Decay Mode of a Heavy Higgs Boson

We reanalyze the extraction of the heavy Higgs boson signal $H\rightarrow W^+W^-\rightarrow \bar\ell\nu,\ell\bar\nu$ $(\ell=e\hbox{ or }\mu)$ from the Standard Model background at hadron supercolliders, taking into account revised estimates of the top quark background. With new acceptance criteria the detection of the signal remains viable. Requiring a forward jet-tag, a central jet-veto, and a large relative transverse momentum of the two charged leptons yields $S/\sqrt B>6$ for one year of running at the SSC or LHC.Comment: LaTex(Revtex), 9 pages, 6 figures (available upon request), MAD/PH/75

Search for the intermediate Mass Higgs Signal at TeV eγe\gamma colliders

The intermediate mass Higgs (IMH) can be abundantly produced through the process $e^-\gamma \rightarrow W^-H\nu$ at TeV $e^-\gamma$ colliders, which are realized by the laser back-scattering method. We search for the signature of $W^-H \rightarrow (jj)(b\bar b)$ plus missing transverse momentum, with and without considering the $b$-tagging. We also analyse all the potential backgrounds from $e^-\gamma \rightarrow W^-Z\nu,\,W^-W^+e^-,\,ZZe^-,\, \bar t b\nu$ and $t\bar t e^-$. With our selective acceptance cuts these backgrounds are reduced to a manageable level. We find that for the entire intermediate mass range 60 -- 150~GeV the Higgs discovery should be viable. We also present detail formulas for the helicity amplitudes of these processes.Comment: Latex(Revtex), 30 pages, 8 figures in postscript format (uuencoded), NUHEP-TH-93-

Modelling magnetic flux emergence in the solar convection zone

[Abridged] Bipolar magnetic regions are formed when loops of magnetic flux emerge at the solar photosphere. Our aim is to investigate the flux emergence process in a simulation of granular convection. In particular we aim to determine the circumstances under which magnetic buoyancy enhances the flux emergence rate (which is otherwise driven solely by the convective upflows). We use three-dimensional numerical simulations, solving the equations of compressible magnetohydrodynamics in a horizontally-periodic Cartesian domain. A horizontal magnetic flux tube is inserted into fully developed hydrodynamic convection. We systematically vary the initial field strength, the tube thickness, the initial entropy distribution along the tube axis and the magnetic Reynolds number. Focusing upon the low magnetic Prandtl number regime (Pm<1) at moderate magnetic Reynolds number, we find that the flux tube is always susceptible to convective disruption to some extent. However, stronger flux tubes tend to maintain their structure more effectively than weaker ones. Magnetic buoyancy does enhance the flux emergence rates in the strongest initial field cases, and this enhancement becomes more pronounced when we increase the width of the flux tube. This is also the case at higher magnetic Reynolds numbers, although the flux emergence rates are generally lower in these less dissipative simulations because the convective disruption of the flux tube is much more effective in these cases. These simulations seem to be relatively insensitive to the precise choice of initial conditions: for a given flow, the evolution of the flux tube is determined primarily by the initial magnetic field distribution and the magnetic Reynolds number.Comment: 12 pages, 15 figures, 2 tables. Accepted for publication in Astronomy and Astrophysic

The role of the intervertebral disc niche on embryonic stem cell differentiation and intervertebral disc regeneration

Poster Session - Orthopedic Regeneration: no. 91DMM 2011 entitled: Re-engineering Regenerative MedicineThe intervertebral disc (IVD) is a highly specialised environment, where cell, water and proteoglycan decrease is strongly associated with disc degeneration, which can lead to back pain. We postulate that the IVD niche is a major factor for IVD cell development and maintenance, and can play a role in progenitor differentiation to become disc cells. The understanding of how stem/progenitor cells develop into IVD cells could potentially facilitate the development of regenerative therapies for degenerated IVD. Here, we aim to introduce human embryonic stem cells (ESCs) into the IVD environment using a model of decellularised bovine disc, and examine how the IVD niche impacts on phenotypic changes in vitro using …postprin

An extendible and ubiquitious e-learning software for foreigners to learn Chinese on iOS-based devices

The larger screen size, mobility, sensing and multi-touch input features of Android or iOS based devices like the iPad or Android tablet PC offer many exciting opportunities for real-life edutainment applications. An example is the learning of Chinese, especially to write Chinese characters in correct stroke sequences, that is typically considered as a difficult task to most foreigners. In this work, we propose an extendible, easy-to-use and ubiquitous e-learning software that was integrated with mini-games to facilitate the learning of Chinese characters on iOS-based devices such as the iPad. To demonstrate the feasibility of our proposal, a prototype of our proposed e-learning software was built on the iOS-based devices so that foreign students can learn to speak and write Chinese anytime and anywhere. Among the various commercially available iOS-based app for learning Chinese, our proposal represents the first attempt to reduce the complexity of learning to write Chinese characters through mini-games while increasing the extendibility of the e-learning software through component-based design. More importantly, it opens up numerous opportunities for further investigations. © 2012 IEEE.published_or_final_versio