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作为密度矩阵一种形式的Wigner函数是量子相空间里的分布。用它描述相对论费密子时,它的通常表达形式为4×4矩阵函数。本文得到相对论带电费密子的2×2矩阵形式的Wigner函数以及它所满足的Liouville方程。这一方程与量子电动力学里带电费密子满足的Dirac方程完全等价。在描述中能核碰撞的Walecka模型里,当只有矢量介子(或标量介于取平均场近似)时,核子满足一定形式的Dirac方程。本文的方程也与之等价。还证明了(2×2)Wigner函数与相对论费密子的波函数在描述量子体系上起着同样的作用。量子体系的可观察量的全部知识都可以通过这里的Wigner函数得到。
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The interdependences of the Iow temperature properties in heavy fermion compounds with the Kondo lattice parameters are obtained from a two-conduction band periodic s-f exchange model by using the Green’s function method .The results indicate that the anomalous Iow temperature properties of the specific heat,resistivity and the static magnetic susceptibility in the heavy fermion systems are all the characteristic fea- tures of the Xondo Iattice. The influences of the pressure on the Kondo temperature TX and on the superconducting transition temperature TC in the heavy fermion systems are also discussed. 相似文献
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从π介子核子散射振幅出发,根据Mandelstam表示和么正条件,对于奇异量子数为零、重子数为1的费米子Regge轨迹,求得了下列结果:(1)位置参数α(s)的解析性,只有右方物理割而无左方动力割,但是左方有从s=0到-∞的运动学割。(2)当s<0时α(s)取复数值,并且还有一条同它成复共轭(在s<0范围内)的Regge轨迹。这一对轨迹它们的J-宇称相同,但是空间宇称相反。02时,α(s)为实数。不同宇称的轨迹对s的依赖不同。(3)讨论了费米子Regge迹在阈能(W0=M+μ)附近的行为。凡是与共振态、束缚态有关的Regge轨迹,α(W0)≠0。求得了在阈附近的表示,定性方面同玻色子轨迹相同。(4)还有一大类Regge轨迹,它们同共振态、束缚态无关,α(W0)=0。这类轨迹在能量趋近阈能时,有无穷多个极点趋于ReJ=0(即我们在费米子情况下得到Gribov-Pomeranchuk极点凝聚现象),这类轨迹当能量由阈下趋于阈时,从J平面左半平面共轭成对趋于ReJ=0;当能量从阈上趋于阈时,成对地从第一和第三象限趋于ReJ=0。所有这些极点实数部分Reα→0比虚数部分Imα→0快一或二个数量级。J平面原点是一个凝聚点,这类“非动力”的Regge轨迹阈行为,无论对玻色子、费米子,以至非相对论势散射,定性都相似(只是凝聚的轴线和点不同)。它们实际上是s矩阵在阈的普遍性质的反映。 相似文献
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CHEN Xue-Jun 《中国物理C(英文版)》1990,14(2):160-163
The expressions of fermion operators in the interacting boson-fermion models including the g-boson have been derived in this short communication. 相似文献
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根据某些重费密子超导系统可能是P波型超导系统的思想,我们讨论了在巡游铁磁体中的超导电性问题。所得结论是在某些特定参数的系统、在某些温度点,可能形成铁磁超导体。
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In this paper, we showed that the eigenvalues of two-dimensional angular momentum of a particle with charge a are integer valued. The problems of a Dirac particle in a field of vortex were discussed. When the vortex tends-to string, we found that the system admits of the existence of θ vacua. For massless fermions, a change in θ is equivalent to a Γs rotation, while the physical result is independent of θ. For massive fermions, CP invariance is broken except for θ=0,π; and the system exhibits the Witten effect. 相似文献
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本文将Schwarzschild度规中的二分量Dirac方程(Brill-Wheeler方程)化为一个单分量的二阶方程,考查了方程的有效势,找出了自旋轨道耦合项。视界附近是一个势垒,当K2>3η2,势垒外侧出现势阱。Dirac粒子将在势阱中某些能级上共振,并穿越势垒被视界吸收。借WKB方法求得准束缚态的能谱,并计算了大|K|情形下的寿命。同样的处理方法还推广至Reissner-Nordstrom度规。
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The properties of fermion causal Green's function is discussed according to the theory of spectral representation. The definition of effective mass is established from the view point of field theory, and the approximate expression of SF' (p) as |p2|«M2 and the asymptotic formula of SF' (p) as p2→+∞ is given. In terms of these result the problem of quark confinement is discussed. We find that: (ⅰ) Based on the theory of spectral re presentation the concept of relative confinement is allowed, and if renormalization effect is strong, the quarks can demonstrate definitely lighter effective mass when they are far away from the mass shell; (ⅱ) Based on the theory of spectral representation the concept of absolute confinement is unallowable, even the absolute confinement is taken as the limit of relative confinement. That is if the concept of absolute confinement is introduced, we must discard a part of elementary hypothesis of spectral representation theory. 相似文献
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In this paper,we derive a boson-fermion hybrid representation for the antisymmetrizer,and obtain an exact mapping of the fermion space onto a hybrid space.The results show that the effect of the antisymmetrizer appears as different kinds of many body forces among the bosons and the fermion. 相似文献
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Two characteristics of the Fermion coherent state are given in this paper. One is the duality of the Fermion coherent state. The other is the indefiniteness of their eigenvalues. The SLAC bag model is also discussed by using the Fermion coherent state methodology. Our zesults agree with the SLAC bounded state iolutions, so that quark confinement can be phenomenally, illustrated.In addition, rje have found a gluon-ball solution and a non-bounded state solution, which are absent from the SLAC theory. Hence,the method of the Fermion coherent state is effective. 相似文献
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本文利用虚坐标方法研究了两个共线Kerr黑洞迭加的时空结构;首次得到了这种情况下视界以内的时空区域,并给出了2z0>(M12-a12)1/2+(M22-a22)1/2时内外无限红移面和奇点随z0变化的情况。由此我们可以看到,对于角动量平行及反平行的两个共线的全同Kerr解来说,当z0→(M2-a2)1/2时,尽管它们视界以外的时空结构分别趋于一个Kerr时空及一个Schwarzschild-NUT时空,但就整个时空结构而言,并非如此。同时,我们还可看到,当2z0>(M12-a12)1/2+(M22-a22)1/2时,Einstoin场方程存在无裸奇点(而不是没有奇点)的解。
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本文提出了处理引力问题的一种可能的设想。采用牛顿引力公式,得到广义相对论中的史瓦西度规;如果考虑质速关系,则得到一种新的度规,否定了黑洞理论。 相似文献
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海洋噪声场的时空相关函数 总被引:1,自引:0,他引:1
本文借助于方向性点源的平面波展开式导出了海洋中噪声场的时空相关函数的普遍表式。用演绎法将该表式用于分层不均匀浅海与分层不均匀深海,建立了噪声场的时空相关函数与海洋环境参数的有机联系。
文中利用接收器附近点(噪声)源的奇性条件简化了浅海中噪声场时空相关函数的计算。接着用简正波理论计算了均匀浅海中噪声场的时空相关函数。 相似文献
文中利用接收器附近点(噪声)源的奇性条件简化了浅海中噪声场时空相关函数的计算。接着用简正波理论计算了均匀浅海中噪声场的时空相关函数。 相似文献
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利用Gilkey的结果,本文求得了标量场、旋量场和矢量场的格林函数的DeWitt-Schwinger展开中的α3系数,并由此求得了de Sitter时空中这些场的真空能量张量在大质量下的近似。
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