Construction of form factors of composite systems by a generalized Wigner-Eckart theorem for the Poincaré group

We generalize the previously developed relativistic approach for electroweak properties of two-particle composite systems to the case of nonzero spin. This approach is based on the instant form of relativistic Hamiltonian dynamics. We use a special mathematical technique to parameterize matrix elements of electroweak current operators in terms of form factors. The parameterization is a realization of the generalized Wigner-Eckart theorem for the Poincaré group, used when considering composite-system form factors as distributions corresponding to reduced matrix elements. The electroweak-current matrix element satisfies the relativistic covariance conditions and also automatically satisfies the conservation law in the case of an electromagnetic current.__________Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 143, No. 2, pp. 258–277, May, 2005.     

High energy heavy ion collisions: Lessons from relativistic heavy ion collider

In this talk, I review the recent results from RHIC and discuss their significance.     

高功率微波器件中脉冲缩短现象的粒子模拟

脉冲缩短是高功率微波器件的一个普遍现象，它阻碍了输出微波能量的进一步提高，是高功率微波研究领域中急待解决的问题.以相对论返波管作为研究对象，运用粒子模拟的方法，研究了器件表面的爆炸发射、电子束电压和电流的脉动对输出微波性能的影响，从中得到了一些有益的结论，指出由强电场引起的慢波系统表面的爆炸发射是产生脉冲缩短的重要因素 ，电子束电流和束电压的脉动也会引起脉冲缩短，并提出了相应的克服方法. 关键词： 高功率微波器件 相对论返波管 脉冲缩短 粒子模拟     

Representations of the Poincaré Semigroup and Relativistic Causality

This paper provides the mathematical tools for addressing issues of two kinds of causality in relativistic scattering theory: general causality, i.e., an effect can only be measured after its cause, and Einstein causality, i.e., no propagation of probability outside of the forward light cone. Starting from Wigner's unitary irreducible representations of the Poincaré group for noninteracting, one particle states, we describe the mathematical tools necessary to describe scattering states, the Lippmann-Schwinger Dirace kets, and to describe resonances and decaying states, the relativistic Gamow ket. An important step for their derivations is the Hardy space hypothesis. Investigating the transformation properties of scattering and resonance states under the dynamical Poincaré semigroup reveals that both kinds of causality result from this hypothesis about nature of the spaces of states and observables.     

多环型半导体探测器的研制

为了改进低能次级束逆运动学核反应角分布的测量，研制了空心的多环型半导体探测器，用来取代沿用多年的X-Y位置灵敏型半导体探测器. 论述了多环型探测器的优越性，介绍了其制作过程和工艺，给出了已研制成功的十一环探测器的性能测试结果.     

相对论Birkhoff系统的第一积分与积分不变量的构造

建立了相对论Birkhoff系统的变分方程,由此证明:由已知系统的一个第一积分,可以构造系统的一个积分不变量,并通过算例说明其结果的应用.     

Perturbed States of a Rotating Relativistic String

We investigate arbitrary small perturbations of the uniform rotation of a rectilinear relativistic string with massive ends. Two classes of such perturbations with different spectra of eigenfrequencies have the form of stationary waves and correspond to string oscillations in the rotation plane and in the orthogonal direction. These states are represented by the Fourier series used to quantize string excitations in the linear neighborhood of the classical rotation. These string oscillations can be used to describe daughter Regge trajectories in the framework of the considered model.     

Binary encounter model for the electron impact K‐shell ionization of atoms

The electron impact K‐shell ionization (EIKSI) cross sections on 18 atomic targets, with the atomic numbers 2 ≤ Z ≤ 92, are calculated using a modified version of the binary encounter approximation (BEA) model. The modified BEA (MBEA), which incorporates both ionic and relativistic corrections and is simpler in application than other existing models, is found to be immensely successful in describing the EIKSI data up to the incident energy of 1 GeV. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

在洛伦兹变换下磁单极的电磁规律

从磁库仑定律出发，用洛伦兹变换导出磁单极的电磁场及其散度，旋度公式和磁单极在电磁场中的受力公式；给出它们的相对论协变形式；最后对讨论推广的麦克斯韦方程组。     

单极巨共振的相对论平均场计算

利用最近完成的相对论平均场理论的计算程序,研究了原子核单极巨共振.计算了¹⁶O,⁴⁰Ca和²⁰⁸Pb的同位旋标量和同位旋矢量单极巨共振.得到的结果与实验符合较好.