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1.
本文介绍了自旋极化电子原子散射的(e,eγ)符合实验的理论基础、实验装置和参数测量方法,描述了符合实验研究主要结果,说明了符合实验研究的物理意义。  相似文献   

2.
电子碰撞原子(e,2e)反应的复极化势   总被引:3,自引:1,他引:2       下载免费PDF全文
研究包括连续通道等非处理通道的复极化势对(e,2e)碰撞过程三重微分截面的影响,即将耦合通道光学势方法得到的复极化势附加到畸变波玻恩近似方法的畸变势中,在靶态的HF近似下,计算了Ar原子和Ne原子在非共面对称几何条件下(e,2e)反应的三重微分截面.对于较高的入射能量,在实验的误差范围内,计算结果与电子动量谱的实验数据符合较好,复极化势的影响很小;对于较低的入射能量,复极化势的作用明显增大. 关键词: 复极化势 (e;2e)反应 三重微分截面 电子动量谱  相似文献   

3.
通过Ar(e, 3e)五重微分截面3维图的理论与实验比较发现, 在低能电子入射的情况下, 理论与实验存在较大的偏差.  相似文献   

4.
(e,2e)反应中末态波函数的动量相关   总被引:2,自引:2,他引:0  
在Berakdar工作的基础上,从动量相关的角度入手,导出了在任意几何条件下的索末菲参量。并由此计算了入射能为50eV和150eV时,电子入射离化He原子的三重微分截面(TDCS)。将计算结果与相应的实验和CCC理论结果进行 现:尽管计算与实验略有偏差,但总体上符合得较好。  相似文献   

5.
通过发展的分子畸变波玻恩近似(MDWBA)方法,把坐标空间的分子多中心问题转化为动量空间的单中心问题,入射电子、散射电子以及被电离电子的波函数都使用了畸变波表象,经过求解动量空间Lippmann-Schwinger方程获得电子的畸变波函数。应用MDWBA方法计算了共面非对称动力学条件下入射能量为100eV 的电子碰撞氢分子(e,2e)反应的三重散射微分截面,并与其它理论和实验结果进行了比较。MDWBA方法的计算结果与实验结果符合的很好。  相似文献   

6.
通过发展的分子畸变波玻恩近似(MDWBA)方法,把坐标空间的分子多中心问题转化为动量空间的单中心问题,入射电子、散射电子以及被电离电子的波函数都使用了畸变波表象,经过求解动量空间Lippmann-Schwinger方程获得电子的畸变波函数。应用MDWBA方法计算了共面非对称动力学条件下入射能量为100eV 的电子碰撞氢分子(e,2e)反应的三重散射微分截面,并与其它理论和实验结果进行了比较。MDWBA方法的计算结果与实验结果符合的很好。  相似文献   

7.
本文使用扭曲波波恩近似方法(DWBA)研究了共面对称条件下钙原子的电子碰撞电离反应((e,2e)反应),在DWBA理论的基础上,考虑了原子极化势和离子极化势对三重微分散射截面的影响.采用发展的DWBA方法,我们研究了出射电子能量从6.75 e V到29.25 e V范围内电子与钙原子的碰撞电离过程,计算了电离三重微分截面.通过与已有理论和实验数据进行比较发现,离子极化势对钙原子的共面对称(e,2e)反应散射微分截面有较大的影响,很好的描述了碰撞电离微分截面的结构效应,特别是在散射角度较小时(≦60o),本文计算结果与实验测量非常一致.  相似文献   

8.
He原子(e,3e)反应中末态波函数的动量相关   总被引:1,自引:1,他引:0       下载免费PDF全文
在前期工作的基础上,进一步考虑了He原子(e,3e)反应中末态四体的动量相关.用改进后的理论计算了高能电子入射双电离He原子的五重微分截面(FDCS).与前期理论相比,所得结果大大地改善了理论曲线与实验结果的吻合程度.  相似文献   

9.
在DS3C模型的基础上,对氦原子(e,3-1e)反应的末态He+2场中未探测电子的屏蔽效应进行了研究.计算了(e,3-1e)过程中入射能为640 eV时,电子入射双电离He原子的四重微分截面(4DCS);讨论了非一级效应对截面结构的影响.所得结果与其他理论计算进行比较发现:文中结果与最新测量的实验数据较好地吻合.  相似文献   

10.
本文使用扭曲波波恩近似方法(DWBA)研究了共面对称条件下钙原子的电子碰撞电离反应( (e,2e)反应 ),在DWBA理论的基础上,考虑了原子极化势和离子极化势对三重微分散射截面的影响。采用发展的DWBA方法,我们研究了出射电子能量从6.75eV到29.25eV范围内电子与钙原子的碰撞电离过程,计算了电离三重微分截面。通过与已有理论和实验数据进行比较发现,离子极化势对钙原子的共面对称(e,2e)反应散射微分截面有较大的影响,很好的描述了碰撞电离微分截面的结构效应,特别是在散射角度较小时(≦60o),本文计算结果与实验测量非常一致。  相似文献   

11.
The prediction for the cross section of e±e±e±e± is given, assuming one photon and Wo exchange. Pure Wo terms and transverse and longitudinal beam polarizations are included.  相似文献   

12.
The predicted cross section for the reaction e+e?→e+e? is presented assuming one photon and W0 exchange. Pure W0 terms and the W0 width are included.  相似文献   

13.
M. Consoli 《Nuclear Physics B》1979,160(1):208-252
Radiative corrections to Bhabha scattering are calculated in the simplest example of non-Abelian gauge theories. A detailed analysis of the higher-order effects is presented and the total differential cross section including weak corrections is evaluated at different angles in an energy range up to 70 GeV per beam. The effects of weak interactions appear to be negligible up to the production of the neutral vector boson.  相似文献   

14.
We present a detailed treatment of the theoretical and experimental aspects of the symmetric (e, 2e) reaction in atoms, molecules and solids. Two experimental arrangements are described for measuring angular correlations and separation energy spectra. the one arrangement employing coplanar and the other noncoplanar symmetric kinematics. The latter arrangement is shown to be particularly suitable for extracting structure information. The basic approximation, the factorized distorted-wave off-shell impulse approximation with fully distorted waves, is shown to correctly describe the reaction in some test cases, as does the phase distortion approximation. At energies of the order of 1200 eV the simple eikonal and plane wave approximations adequately describe the valence shell cross sections for light atoms and molecules containing first row elements. Energy independent structure information is obtained on: (a) shapes and magnitudes of the square of the momentum space wave functions for individual electron orbitals; (b) separation energies for individual ion eigenstates; (c) the characteristic orbital of each state; and (d) spectroscopic factors describing the probability that an eigenstate contains the principal configuration of a hole in the characteristic orbital for each eigenstate. Comparison is made with photoelectron spectroscopy and Compton scattering, since they separately yield some of the information obtained by the (e, 2e) method. A brief summary is given of other electron-electron coincidence experiments.  相似文献   

15.
We calculate the cross-section for the production ofe + e ?γγγ ine + e ? annihilation. The results are in agreement with the first observation of such a process by the ASP experiment at SLAC. The calculation also provides another example of the power of ‘spinor techniques’ in calculating Feynman amplitudes.  相似文献   

16.
We present the properties of 105 events of the form e+ + e? → e+- + μ? + missing energy, in which no other charged particles or photons are detected. The simplesthypothesis compatible with all the data is that these events come from the production of a pair of heavy leptons, the mass of the lepton being in the range 1.6 to 2.0 GeV/c2  相似文献   

17.
The analysis of the lepton angular distribution at LEP is reviewed and the specific concerns in the case ofe + e final state are singled out. Studies of the physical information contained in thee + e angular distribution are shown to justify the need for a new approach. Two different solutions that enable the complete use of the angular distribution information for the extraction of theZ parameters are presented. We show that these approaches have accuracies well above the future experimental needs.  相似文献   

18.
We give the spectrum in momentum and angle of directly produced γ's in e+e?γ + hadrons, and show that in QCD if p2 of the recoil hadron jet relative to the photon is large, the leading logarithmic corrections to the lowest order result are absent. This process is therefore of great value in learning whether QCD actually governs quark dynamics.  相似文献   

19.
We present a complete set of rotationally invariant observables (Hl) which characterizes the ‘shapes’ of final states in e+e? annihilation. They are infrared stable when calculated in QCD perturbation theory. We compare the ‘shapes’ of final states from the processes e+e?qq, e+e?qq(G) and from the three-gluon decays of heavy vector mesons. We also consider the production and decay of heavy quarks and leptons. Using a realistic model for the development of hadron jets, we find that for c.m. energies above about 10 GeV, these processes may be clearly distinguished by their distributions in the Hl. We indicate how our analysis may be extended to deep inelastic lepton-hadron interactions and hadron-hadron collisions involving large transverse momenta.  相似文献   

20.
We study the properties of toponium states and their production in e+e? collisions with special emphasis on the mass region accessible to SLC and LEP. A formalism for toponium -Z mixing is developed that is applicable for arbitrary mass differences between Z and the toponium state. It is shown that simple lowest-order perturbation theory is equivalent to the mixing formalism up to an accuracy better than one percent in the entire energy range we investigate. The results are illustrated by calculations performed in the framework of two QCD-inspired potential models which predict about 10 narrow states in the mass range around the Z. The mixing effects on the properties of Z are small even in the case of degenerate Z and toponium masses. The effect of electroweak interferences on and around toponium are studied, and analytic forms for cross sections and asymmetries before and after energy smearing are presented. We show that high radial excitations of toponium states below threshold may be difficult to disentangle from the continuum states. A brief survey of the properties of heavy bottom-type quarkonia concludes the paper.  相似文献   

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