Cooper pairs? magnetic moment in MCFL color superconductivity

We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.     

一种简易云雾室的制作

本文利用自制云雾室把微观粒子的运动转化为宏观现象，从而供实验观察和研究。     

Particle-number-conserving analysis of multiquasiparticle bands in ~(177)Lu

The experimental one-, three-, and five-quasiparticle bands in ~(177)Lu are analyzed by the particle-number conserving (PNC) method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia are reproduced very well by PNC calculations with us free parameter.     

Muon g-2 discrepancy:new physics or a relatively light Higgs?

After a brief review of the muon g-2 status,we discuss hypothetical errors in the Standard Model prediction that might explain the present discrepancy with the experimental value.None of them seems likely.In particular,a hypothetical increase of the hadroproduction cross section in low-energy e+e-collisions could bridge the muon g-2 discrepancy,but it is shown to be unlikely in view of current experimental error estimates.If,nonetheless,this turns out to be the explanation of the discrepancy,then the 95% CL upper bound on the Higgs boson mass is reduced to about 135 GeV which,in conjunction with the experimental 114.4 GeV 95%CL lower bound,leaves a narrow window for the mass of this fundamental particle.     

应用角点匹配实现目标跟踪

角点特征是图像的一个重要局部特征,因其具有计算量小、匹配简单以及旋转、平移、缩放不变的性质,而在图像配准与匹配、目标识别、运动分析、目标跟踪等应用领域都起着非常重要的作用。本文提出了一种新的基于角点特征的向量匹配方法,该方法利用Harris算子检测出目标角点,通过角点的矩特征形成目标的特征向量,最后通过对序列图像的目标特征向量进行匹配来实现目标跟踪。此算法在一般情况下能匹配80%以上角点,在遮挡情况下仍能正确匹配70%左右,处理速度达到20 frames/s,满足了实时要求。实验结果证明此方法可有效地抵御目标的变形和遮挡情况。     

旋转带电体磁矩计算的若干法则与算例

本文在文献 [1]、[2 ]等的基础上给出关于旋转带电体的磁矩计算的若干法则 ,均以定理形式表达 ,并列表枚举其相关算例     

用雅可比-傅里叶矩进行图像描述

提出了雅可比—傅里叶矩,它是用雅可比多项式作为径向函数,用傅里叶因子作为角向函数构造而成的,是广义正交傅里叶—梅林矩。经过归一化处理后的雅克比—傅立叶矩具有平移、尺度、旋转、灰度多畸不变性。从归一化图像重建误差、噪声灵敏度等方面对雅可比—傅里叶矩的图像描述能力进行了研究,结果显示雅可比—傅里叶矩在各种参量选择的情况下,具有良好的图像描述和抗噪声能力,是一个优良的图像特征。以前的研究多为单纯构建某一个函数,而现在将其扩展为构建一个函数族,开阔了矩描述量的研究视野。     

矩量法研究平面波导点缺陷引起的散射损耗

对平面波导工艺过程里出现的点缺陷,如气泡、灰尘颗粒等对平面波导内光场造成的散射提供了一种简单而又实用的计算方法。计算基于格林函数方法,并利用矩量法求解积分方程,采用分块矩阵优化算法,使得算法的计算时间直接与点缺陷大小相关,提高了效率。证明了一定大小的点缺陷在特定的波长处会产生很大的散射损耗,证明点缺陷的散射损耗依赖于缺陷大小和光学性质而与其在波导中的位置无直接关系。以二氧化硅平面波导为例,分析了对中心波长1．55μm的入射光场,分别存在气泡和灰尘颗粒两种点缺陷时,散射损耗随点缺陷大小的关系特性,指出工艺过程特别应该避免某些孔径的点缺陷。     

密度泛函理论研究闪锌矿结构CrTe和VTe半金属铁磁性的稳定性

采用基于密度泛函理论的全势能线性缀加平面波方法对闪锌矿结构CrTe和VTe的电子结构进行自旋极化计算.闪锌矿相CrTe和VTe处于平衡晶格常数时都是半金属性的,它们自旋向下子能带的带隙分别是2.82 eV和2.70 eV,半金属隙分别是0.89 eV和0.33 eV.使晶体相对于平衡晶格在±10%的范围内发生各向同性形变,对闪锌矿相CrTe和VTe的电子结构进行计算,计算结果表明相对于平衡晶格的各向同性形变分别为-6%～10%和-3%～10%时它们仍然具有半金属性质;与此同时,在以上相同的形变范围内闪锌矿相CrTe和VTe的总磁矩分别稳定于4.00μB/formula和3.00μs/formula.在晶体相对于平衡晶格发生各向同性形变分别为-6%～10%和-3%～10%时,闪锌矿相CrTe和VTe能保持半金属铁磁性.