A relativistic correction to semiclassical charmonium

It is shown that the relativistic linear potentials, introduced by the author within the particle à la Wheeler-Feynman direct-interaction (AAD) theory, applied to the semiclassically quantized charmonium, yield energy spectrum comparable to that of some known models. Using the expansion of the relativistic linear AAD potentials in powers ofc ^–1, the charmonium spectrum, given as a rule by Bohr-Sommerfeld quantization of circular orbits, is extended up to the second order of relativistic corrections.     

Approximate Born-Infeld effects on the relativistic hydrogen spectrum

The Born-Infeld form of the hydrogen atom has a spectrum that can be used to determine the physical viability of the theory, and place an experimentally relevant bound on the single parameter found in it. We compute this spectrum using the relativistic Dirac equation, and a form of the Born-Infeld potential that approximates the self-field corrections of the electron. Using these together, we can establish that if the Born-Infeld nonlinear electrodynamics is to be physically relevant, it must contain a fundamental constant that is well below the original value proposed by Born. This work extends the original Schrödinger spectrum from Carley and Kiessling (2006) [1] for the self-field correction, and shows that using the Dirac equation introduces minor corrections - but also gives access to a range for the fundamental constant that is below that attainable from non-relativistic considerations.     

Rearrangement term with relativistic density-dependenthyperon potentials

An appropriate density dependence of hyperon potentials is important for the stiffening of the equation of state and massive neutron stars. To persist in covariance and thermodynamic consistency, the rearrangement term is indispensable. In this work, we derive the rearrangement term for hyperon potentials with arbitrary density-dependence. The importance of the rearrangement term is also exhibited in numerical instances.     

A verification of the relativistic correction for electro-static electron spectrometers

The relativistic predictions for the non-linear calibration of a spherical sector electron spectrometer, operated with retardation in the constant δE/E mode, is verified to an accuracy of ± 0.05 eV over the energy range 0–2500 eV. The verification, involving the comparison of the energy deficit measured between the energy of peaks in the constant δE mode with that in the constant δE/E mode, is obtained by the use of an elastically reflected electron beam at 100 eV intervals over the full energy range. The energy deficit, for a VG Scientific ESCA 3 Mk II with a retard ratio of 1.656, increases from zero at 0 eV to 2.28 eV at 2500 eV. It is concluded that the spectrometer is very well behaved and that the established relativity theory is accurately verified in this investigation.     

氦原子1sns组态能量及其相对论修正

利用Mathemtica语言开发了一套计算氦原子1sns组态能量的程序.提出了构造氦原子1sns组态波函数的新方法,利用Rayleigh.Ritz变分法对氦原子1sns(,n=2-5)组态的非相对论能量进行了计算,并计算了其相对论修正值(包括质量修正、单体达尔文修正、双体达尔文修正、自旋一自旋接触相互作用修正、轨道.轨道相互作用修正),计算结果与实验值相当接近.     

Static baryon properties in a relativistic quark model with centre-of-mass correction

The static properties such as magnetic moments, charge radii and axial vector coupling constant ratios of the quark core of baryons in the nucleon octet have been calculated in an independent-quark model based on the Dirac equation with equally mixed scalar-vector potential in linear form in the current quark mass limit. The results obtained with appropriate corrections due to centre-of-mass motion are in reasonable agreement with experimental data. The magnetic moments of the quark core of baryons in the charmed andb-flavoured sectors have also been calculated with this model and the overall predictions so obtained compare very well with other model predictions.     

Sea correction to the quenched nucleon σ term

A recent quenched lattice QCD estimate of the nucleon σ term leads to a value which is roughly half of the experimental value. We estimate the non-strange sea correction to be dominated by the σ-meson pole contribution, which accounts satisfactorily for the discrepancy. This large non-strange sea content in the nucleon does not necessarily imply a large strange sea content.     

Approximate solutions of SchrSdinger equation for Eckart potential with centrifugal term

The approximate analytical solutions of the Schrodinger equation for the Eckart potential are presented for the arbitrary angular momentum by using a new approximation of the centrifugal term. The energy eigenvalues and the corresponding wavefunctions are obtained for different values of screening parameter. The numerical examples are presented and the results are in good agreement with the values in the literature. Three special cases, i.e., s-wave, ξ= λ=1, and β=0, are investigated.     

Phonon conductivity correction term: Application to P-doped Ge

The role of the characteristic temperature θ¹ (which differentiates peripheral phonons from non-peripheral phonons) in the study of the phonon conductivity correction term due to three phonon normal processes, has been studied for the first time. The study is made for P-doped Ge in the temperature range 1–5 °K for the different values of θ¹ in the range 8–24 °K as an example.     

氦原子1sns组态能量及其相对论修正

利用Mathemtica语言开发了一套计算氦原子1sns组态能量的程序.提出了构造氦原子1sns组态波函数的新方法,利用Rayleigh-Ritz变分法对氦原子1sns(n=2—5)组态的非相对论能量进行了计算,并计算了其相对论修正值(包括质量修正、单体达尔文修正、双体达尔文修正、自旋-自旋接触相互作用修正、轨道-轨道相互作用修正),计算结果与实验值相当接近. 关键词： 氦原子 能量 变分法 Mathemtica程序     

Spin symmetry in the relativistic modified Rosen-Morse potential with the approximate centrifugal term

By applying a Pekeris-type approximation to the centrifugal term, we study the spin symmetry of a Dirac nucleon subjected to scalar and vector modified Rosen-Morse potentials. A complicated energy equation and associated two-component spinors with arbitrary spin-orbit coupling quantum number k are presented. The positive-energy bound states are checked numerically in the case of spin symmetry. The relativistic modified Rosen-Morse potential cannot trap a Dirac nucleon in the limiting case α→ 0.     

单模块直线变压器脉冲前沿

从理论上对直线变压器驱动源（LTD）输出脉冲波形的前沿进行了分析,研究了不同前沿畸变情况下对应的电路参数,并给出了计算方法,得到了相对电压和相对时间的关系曲线。根据理论分析设计了单模块LTD,并根据设计参数进行了数值模拟,模拟得到的输出脉冲前沿约30 ns、平顶约130 ns、幅值约125 kV。最后进行了单模块LTD实验,测得输出脉冲前沿约35 ns、平顶约130 ns、幅值约125 kV的输出脉冲,与模拟结果基本一致。由于负载不完全匹配等因素的影响,波形后沿较差且有振荡,但仍符合设计要求。     

Relativistic correction to the triton binding energy in the framework of relativistic Hamiltonian dynamics

The relativistic correction to the triton binding energy approximated to the order (v/c)² is calculated in the framework of relativistic Hamiltonian dynamics. We discuss the generator representation of the Poincaré group for three relativistic particles and its connection with the Feynman diagrams in the infinite-momentum frame (the light-front dynamics). The relativistic correction enhances the attraction in the three-nucleon system. The five-channel calculation with the Reid soft-core potential yeilds the result =–0.54 MeV, which is governed mainly by theD-wave contribution. TheS-wave contributions to are only –0.10 MeV.     

基于相对论修正的超快电子枪偏转扫描系统的理论研究

对工作于扫描状态下的飞秒电子衍射系统电子枪偏转量的计算方法作了理论研究,讨论了超快电子脉冲的测量方法,比较了相对论效应对电子束的偏转量及对电子束脉冲宽度的计算结果的影响,并做了相应的数值计算。计算结果显示,在忽略了电场的边缘效应等因素后,电子束轴向速度的相对论修正与否对偏转距离和电子束脉冲宽度的影响分别达到61.4 mm和65 fs。研究结果对超快电子枪偏转扫描系统的设计、对超短电子脉冲宽度的测量方法,尤其是对超短电子脉冲宽度的测量过程中的同步实验具有一定的指导意义。     

Approximate solutions of Schrdinger equation for Eckart potential with centrifugal term

The approximate analytical solutions of the Schrdinger equation for the Eckart potential are presented for the arbitrary angular momentum by using a new approximation of the centrifugal term. The energy eigenvalues and the corresponding wavefunctions are obtained for different values of screening parameter. The numerical examples are presented and the results are in good agreement with the values in the literature. Three special cases, i.e., s-wave, ξ = λ = 1, and β = 0, are investigated.     

Leading relativistic correction to the interaction coefficients between atoms and molecules using Borel integral II

Lower and upper bounds to the leading relativistic correction to the interaction coefficients between H, He, Ne, Kr, and Xe atoms, and H₂ and N₂ molecules have been evaluated by using Borel integral for the dynamic dipole polarizability. Our results for these bounds are in agreement with others.     

Dispersive effects and correction term in two-mode phonon conduction model for Ge

A complete analysis of the phonon conductivity κ, still lacking in the literature, is presented in the two-mode conduction model for Germanium. First a method is derived from which the correction term κ_c of the Callaway model is separated into its longitudinal and transverse parts and then the effects of strong phonon dispersion and the role of longitudinal and transverse phonons on κ_c are studied. For this purpose we have also proposed some new empirical expressions for the three phonon relaxation rates τ_3ph⁻¹'s which are valid in the entire temperature range. This improvised model, when applied simultaneously to the phonon conductivity data of both normal and enriched Ge, yields some new results. These are (i) κ_c neglected by the earlier workers in the two-mode phonon conduction model, gives a substantial contribution beyond the conductivity maximum and (ii) the longitudinal phonons are the major carriers of heat at high temperature.     

On the existence of the logarithmic correction term in black hole entropy-area relation

In this paper we consider a model universe with large extra dimensions to obtain a modified black hole entropy-area relation. We use the generalized uncertainty principle to find a relation between the number of spacetime dimensions and the presence or vanishing of logarithmic prefactor in the black hole entropy-area relation. Our calculations are restricted to the microcanonical ensembles and we show that in the modified entropy-area relation, the microcanonical logarithmic prefactor appears only when spacetime has an even number of dimensions.