摘要：
We employ the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz (CIA) to study the leptonic decays of vector mesons. The structure of hadron-quark vertex function Gamma is generalized to include various Dirac covariants (other than i gamma dot epsilon) from their complete set. They are incorporated in accordance with a naive power counting rule order by order in powers of the inverse of the meson mass. The decay constants for rho omega and phi mesons are calculated with the incorporation of leading order covariants. Comment: 18 pages, 1 table and 1 figure in pdf file; Version to appear in JPG
摘要：
The recent measurements by CLEO for the inclusive J/Ψ and Ψ(2S) production in Υ(1S) decay and our previous calculation are analyzed. The J/Ψ momentum spectrum and the production ratio of Ψ(2S) versus J/Ψ favor Υ→J/Ψ(Ψ(2S))+cc¯g as the dominant contribution. We point out that the differences between the experimental data and our previous results are mainly originated from the setting of the parameter charm quark mass. Encouraged by this result, we investigate the associate strange particle enhancement as a probe for the open charm particles in Υ→J/Ψ(Ψ(2S))+cc¯g.
作者机构：
[Tan Rong; Tan, R; Li Gao-Xiang] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Tan Rong] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
Spontaneous Decay;Infinitely Permeable
摘要：
We present the explicit expression of the spontaneous decay rate of a quadrupole placed between two parallel plates (one or both the plates have infinite permeability, i.e. μ→∞). It is found that the spontaneous decay rate displays oscillations with the position of the quadrupole, and the oscillations exhibit a symmetric profile with respect to the central plane of the plates for the symmetric models and lack the symmetry for the asymmetric model.
期刊：
2006 INTERNATIONAL CONFERENCE ON COMMUNICATIONS, CIRCUITS AND SYSTEMS PROCEEDINGS, VOLS 1-4: VOL 1: SIGNAL PROCESSING,2006年:659-663
通讯作者：
Xie, Wenwu
作者机构：
[Liu, Shouyin; Xie, Wenwu] Huazhong Normal Univ, Dept Elect & Informat Engn, Wuhan 430079, Peoples R China.
通讯机构：
[Xie, Wenwu] H;Huazhong Normal Univ, Dept Elect & Informat Engn, Wuhan 430079, Peoples R China.
会议名称：
2006 International Conference on Communications,Circuits and Systems(第四届国际通信、电路与系统学术会议)
会议时间：
2006-06-25
会议地点：
广西桂林
会议论文集名称：
第四届国际通信、电路与系统学术会议
摘要：
In this work, first, we deduce the probability density function (PDF) and the cumulative distribution function (CDF) of the fading coefficient envelope, based on the correlated modified Weibull fading model. To simply the discussion, a system with two transmit antennas and one receive antenna is considered, namely dual-branch system. Secondly, the outage probability of the dual-branch system under the correlated modified Weibull fading channel is derived. And the effects of the correlation coefficient and the Weibull fading parameter on the performance are analyzed by computer simulation for QPSK modulation. Finally, we present several simulations to validate our analysis. Results show that the simulation curves fit our analytical results correctly.
摘要：
We study the effects of gauge-field fluctuations on the free energy density of a homogeneous color superconductor in the color-flavor-locked (CFL) phase. Gluonic fluctuations induce a strong first-order phase transition, in contrast to electronic superconductors where this transition is weakly first order. The critical temperature for this transition is larger than the one corresponding to the diquark pairing instability. The physical reason is that the gluonic Meissner masses suppress long-wavelength fluctuations as compared to the normal conducting phase where gluons are massless, which stabilizes the superconducting phase. In weak coupling, we analytically compute the temperatures associated with the limits of metastability of the normal and superconducting phases, as well as the latent heat associated with the first-order phase transition. We then extrapolate our results to intermediate densities and numerically evaluate the temperature of the fluctuation-induced first-order phase transition, as well as the discontinuity of the diquark condensate at the critical point. We find that the London limit of magnetic interactions is absent in color superconductivity.
作者：
Li, W.*;Wang, Q. A.;Nivanen, L.;Le Mehaute, A.
期刊：
Physica A-Statistical Mechanics and its Applications,2006年368(1):262-272 ISSN：0378-4371
通讯作者：
Li, W.
作者机构：
Inst Super Mat Mans, F-72000 Le Mans, France.;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Li, W.] Inst Super Mat Mans, 44 Ave FA Bartholdi, F-72000 Le Mans, France.
通讯机构：
[Li, W.] I;Inst Super Mat Mans, 44 Ave FA Bartholdi, F-72000 Le Mans, France.
摘要：
Aligned ZnO nanotubes were synthesized in the presence of Polyethylene Glycol (PEG 2000) by means of a simple two-step solution-phase procedure. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectrometry (EDS) and photo luminescence (PL) spectrum were used to characterize the structure, morphology and optical property of the sample. The results showed that PEG played a significant role in the formation of ZnO nanotubes. The ZnO crystals were grown in hexagonal hollow tube form with a well faceted end and side surfaces. The diameter of each ZnO nanotubes has some variation from bottom to top. The room-temperature photo luminescence spectrum of the tubes revealed a strong and sharp UV emission band at 390 nm and a weak and broad green emission band at 530 nm. Possible growth mechanism of the ZnO nanotubes is briefly discussed. (c) 2005 Elsevier B.V. All rights reserved.
作者机构：
[Jia, Y] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Biophys, Wuhan 430079, Peoples R China.;CCAST, World Lab, Beijing 100080, Peoples R China.;Jianghan Univ, Dept Phys, Wuhan 430056, Peoples R China.
通讯机构：
[Jia, Y] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
A circadian oscillator driven by external noise and internal noise has been studied by use of the chemical Langevin equation method. When the system is near a Hopf bifurcation and driven by internal noise only, it is found that the coherence resonance phenomenon can be induced by the internal noise. When the system is simultaneously driven by internal and external noise, it is found that external-noise coherence resonance can be suppressed by internal noise, while internal-noise coherence resonance can be enhanced by modulation of the external noise intensity in a certain range of noise intensity. Another interesting result is that the external noise can regulate the optimal system size when the internal-noise coherence resonance occurs.
作者机构：
[Jia, Ya; Li, Jia-Rong] School of Physics, Huazhong Normal University, Wuhan 430079, China;Department of Physics, Xianning College, Xianning 437000, China;Department of Physics, Jianghan University, Wuhan 430056, China;[Wang, Jiu-Yun] School of Physics, Huazhong Normal University, Wuhan 430079, China<&wdkj&>Department of Physics, Xianning College, Xianning 437000, China;[Zhu, Chun-Lian] School of Physics, Huazhong Normal University, Wuhan 430079, China<&wdkj&>Department of Physics, Jianghan University, Wuhan 430056, China
通讯机构：
[Wang, J.-Y.] S;School of Physics, , Wuhan 430079, China
摘要：
We have measured the ratio of the population of Ni neutral atoms sputtered into the a3D3 metastable state to that into the a3F4 ground state using two-color ionization schemes. The ratio is 2.27±0.31 for Ni, 2.34±0.17 for Ni3Al, and 2.61±0.27 for NiAl. Within experimental error, we observed no effect of the valence band electron structure on the population ratio. We suggest that sputtered atoms should experience resonant neutralization and nonradiative relaxation. Before neutralization, departing Ni ions from the surface have an electron configuration of 3d9 or 3d84s1. The 4s electron orbital of the departing ions captures a valence electron and formed nascent Ni atoms in the D (3d94s1) and F (3d84s1) states, respectively. The population inversion can be attributed to the character of ions and atoms of Ni. Because of the character of Ni ions, most of the ejected nascent Ni atoms are in the D state. The character of Ni atoms leads to a low relaxation rate of the D to F state. Many of the nascent Ni atoms in the D state can survive and so the population inversion was observed.
