Leptogenesis bound on spontaneous symmetry breaking of global lepton number

We propose a new class of leptogenesis bounds on the spontaneous symmetry breaking of global lepton number. These models have a generic feature of inducing new lepton number violating interactions, due to the presence of the Majorons. We analyzed the singlet Majoron model with right-handed neutrinos to find that the lepton number should be broken above 10⁵ GeV to realize a successful leptogenesis because the annihilations of the right-handed neutrinos into the massless Majorons and into the standard model Higgs should go out of equilibrium before the sphaleron process is over. We then argue that this type of leptogenesis constraint should exist in the singlet–triplet Majoron models as well as in a class of R-parity violating supersymmetric Majoron models.     

Observations on the Wilson fermions in the ϵ regime

We make several observations concerning the low quark mass region with Wilson fermions and how this is connected with the ? regime in the continuum. A transition from tiny cutoff effects to rather large discretization errors would take place in general with Wilson fermions if we lower the quark mass at finite lattice spacing. We argue that these two regions exhibit rather different behaviours concerning the coupling between cutoff effects and zero-modes. We interpolate between these two regimes adding to the continuum ? regime formulae, in the spirit of the Symanzik expansion, the relevant operators parametrising the leading cutoff effects. We compute the partition function, the chiral condensate, scalar and pseudo-scalar correlation functions. The final formulae can be used to fit lattice data to extract physical low energy constants, and to estimate systematic uncertainties coming from discretization errors. Moreover they suggest ways on how to remove these cutoff effects, the core of which are captured by the continuum zero modes.     

Ultrarelativistic Bose–Einstein gas on Lorentz symmetry violation

In this paper, we study the effects of Lorentz Symmetry Breaking on the thermodynamic properties of ideal gases. Inspired by the dispersion relation coming from the Carroll–Field–Jackiw model for Electrodynamics with Lorentz and CPT violation term, we compute the thermodynamics quantities for a Boltzmann, Fermi–Dirac and Bose–Einstein distributions. Two regimes are analyzed: the large and the small Lorentz violation. In the first case, we show that the topological mass induced by the Chern–Simons term behaves as a chemical potential. For Bose–Einstein gases, a condensation in both regimes can be found.     

Single-flavor Abelian mirror symmetry on ℝℙ2 × S1

Physics of Atomic Nuclei - The superconformal index on ℝℙ2 × S1 can be derived exactly by the localization technique and applied to the direct proof of Abelianmirror symmetry. We...     

Pellet Enhanced Performance on the HL-2A Tokamak

Enhanced confinement has been achieved by the centre fuelling of pellet injection on the HL-2A tokamak. The energy confinement time increases from 50ms to 140ms after the pellet injection. Experimental results show that the improvement of the confinement is related to the decrease of the electron heat transport. Several phenomena which may lead to the improved confinement have been observed in the experiments. After the pellet injection the hollow electron temperature profile and the peaked electron density profile can be sustained for about 200ms, but the improved confinement remains at about 500ms. Sawtooth features and MHD modes have been observed by soft x-ray array and the Mirnov probes. The weak （or reversed） magnetic shear is thought to be an important cause of the low electron heat transport.     

Localized Mode Enhanced Coupler Based on Quasi-One-Dimensional Photonic Crystal Microstrip

We propose a novel localized mode enhanced (LME) coupler based on quasi-one-dimensional photonic crystal microstrips, which is promising to be applied in wavelength division multiplexed microwave communication systems. Compared to the traditional microstrip coupler, the LME structure has two advantages: high efficiency and frequency selectivity. Even in a relatively far coupling distance, this structure can still achieve a high efficiency about 50%. The frequency selectivity can be realized by simply tuning the distance between two transmission lines.     

The Pellet Enhanced Performance on the HL-2A Tokamak

Improved confinement during the fuelling is one of the most important subjects for the tokamak research. Experiments have confirmed that anomalous transport is caused by turbulences driven by temperature and density gradient in plasma. Pellet injection is not only an important fuelling method, but also is an efficient tool for controlling the plasma pressure and current profile. The improved energy confinement has been observed in many tokamaks with center pellet injection since 1980＇s.     

Comments on ‘Enhanced piezoresistivity in Ni-silicone rubber composites’

This paper describes the accepted meaning of the term ’negative resistance’ and its use in the literature, and discusses the features in the previously published data on QTC TM (market name of a metal-polymer composite) that show that the non-linear, hysteretic current voltage characteristics are not caused by Joule heating. The benefit of the high metal filler loading in QTC TM and other unique features of this composite are reviewed.     

Thermal effects on saxion in supersymmetric model with Peccei–Quinn symmetry

We consider supersymmetric model with Peccei–Quinn symmetry and study effects of saxion on the evolution of the universe, paying particular attention to the effects of thermal bath. The axion multiplet inevitably couples to colored particles, which induces various thermal effects. In particular, (i) saxion potential is deformed by thermal effects, and (ii) coherent oscillation of the saxion dissipates via the interaction with hot plasma. These may significantly affect the evolution of the saxion in the early universe.     

Relaxing the cosmological constraints on unparticle dark component

Unparticle physics has been an active field since the seminal work of Georgi. Recently, many constraints on unparticles from various observations have been considered in the literature. In particular, the cosmological constraints on the unparticle dark component put it in a serious situation. In this work, we try to find a way out of this serious situation, by including the possible interaction between dark energy and the unparticle dark component.     

Theoretical and experimental study on strip reflection coefficient of different crystal symmetry class

The closed-form expressions on strip reflection coefficients of tetragonal 4/mmm, hexagonal 6/mm and trigonal 3m crystal, etc, were derived, which are different from that of cubic m3m crystal published. The reflection coefficients of short-circuited Al grating and groove grating on 112°rotated X-cut Y-propagation LiTaO3 are then given. The reflection property of a short-circuited Al -recessed groove grating on 112°LiTaO3 has been experimentally studied and the condition without internal reflection was achieved. It concludes that the structure of single finger without internal reflection can be realized by the short-circuited Al -recessed groove grating on 112°LiTaO3 and thereafter a pass-band filter with central frequency at 255 MHz, bandwidth about 10 MHz, pass-band ripples less than 0.4 dB was yielded.     

Topological constraints on solar loop plasma instabilities and Alfvén waves

Inhomogeneous plasmas-solar instabilities-are investigated by using the techniques of classical differential geometry for curves, where the Frenet torsion and curvature describe completely the motion of a curve. In our case, the Frenet frame changes in time and also depends upon the other coordinates, taking into account the inhomogeneity of the plasma. The exponential perturbation method, so commonly used to describe cosmological perturbations, is applied to the magnetohydrodynamic (MHD) plasma equations to find modes describing Alfvén wave propagation in the medium of planar loops. Stability is investigated in the imaginary axis of the spectra of complex frequencies ω, i.e. m (ω) ≠ 0. A pratical guide for experimental solar physicists is given by computing the twist of force-free solar loops, which generalizes the Parker formula relating the twist to the Frenet torsion. In our expression the twist of the solar loops also depends on the abnormality of the normal vector of the frame.      

Chiral color quark symmetry and possible constraints on the <Emphasis Type="Italic">G</Emphasis>′-boson mass from tevatron and LHC data

A gauge model featuring a chiral color symmetry of quarks was considered, and possible manifestations of this symmetry in proton-antiproton and proton-proton collisions at the Tevatron and LHC energies were studied. The cross section s_{t[`(t)]</sub>\sigma _{t\bar t} for the production of t[`(t)]t\bar t quark pairs at the Tevatron and the forward-backward asymmetry A_FB<sup>p[`(p)]</sup>A_{FB}^{p\bar p} in this process were calculated and analyzed with allowance for the contributions of the G′-boson predicted by the chiral color symmetry of quarks, the G′-boson massm <sub>G′</sub> and the mixing angle θ <sub>G</sub> being treated as free parameters of the model. Limits on m <sub>G′</sub> versus θ <sub>G</sub> were studied on the basis of data from the Tevatron on s<sub>t[`(t)]}\sigma _{t\bar t} and A_FB^p[`(p)]A_{FB}^{p\bar p}, and the region compatible with these data within one standard deviation was found in the m _G′-θ _G plane. The region ofm _G′-mass values that is appropriate for observing the G′-boson at LHC is discussed.     

Surface—Enhanced Raman Scattering of Humic Substances Adsorbed on Silver Sols

Surface - enhanced resonance Raman scattering of humic and fulvic acids from various sources adsorbed on silver sols were investigated. Only in acidic conditions, the strong SERRS spectra of humic substances were observed and these results revealed the disordered graphite structures of almost all the samples. The detection limits were 5 – 80 ug/L. Thus SERRS appears very promising in analysis and detection of humic substances in complex systems as well as real environment.     

First-principles perspectives on detection properties of sulphur mustard gas using novel electroresistive ϵ-Arsenene nanosheet device

ABSTRACT

The feasibility of using ?-Arsenene (?-As) nanosheet device to detect the target vapour, 2-chloroethyl chloromethyl sulphide (one of sulphur mustard gas molecule) is investigated in the research by applying density functional theory method. The firm nature of ?-As nanosheet is verified using formation energy, and the electronic features are estimated for the pristine and target vapour adsorbed ?-As sheets. In addition, the adsorption attributes are computed to resolve the most preferred site of target vapour adsorption. Moreover, the transmission and current–voltage characteristics are explored to validate the modification in the resistivity and conductivity of ?-As device upon adsorption of the target vapour. Furthermore, the selectivity of ?-As sheets towards humidity, CO and CO₂ are also studied and ?-As sheets are highly selective to sulphur mustard gas molecules. The properties examined emphasise the employment of ?-As nanosheet molecular device to act as a chemo-sensor towards the target vapour, 2-chloroethyl chloromethyl sulphide.     

Enhanced Electroluminescent Efficiency Based on Functionalized Europium Complexes in Polymer Light-Emitting Diodes

Efficient red polymer light-emitting diodes are fabricated with the single active layer from the blends of poly（N- vinylcarbazole） （PVK） in the presence of 30 wt. % electron-transporting compound 2-（4-biphenylyl）-5-（ptert- butylphenyl）-1,3,4-oxadiazole （PBD） and europium complexes. The polyphenylene functionalized europium com- plex shows an enhanced electroluminescent efficiency due to the large site-isolation effect. For the polyphenylene functionalized europium complex, the maximum external quantum efficiency of 1.90% and luminous efficiency of 2.01 cd A^-1 are achieved with emission peak at 612nm. The maximum brightness is more than 300cd m^-2.