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 共查询到20条相似文献,搜索用时 31 毫秒
1.
《Nuclear Physics A》1997,627(4):599-619
We study the inclusive (e, eN), (e, eNN), (e, eπ), (e, eπN) reactions in nuclei using a Monte Carlo simulation method to treat the multichannel problem of the final state. The input consists of reaction probabilities for the different steps evaluated using microscopical many body methods. We obtain a good agreement with experiment in some channels where there is data and make predictions for other channels which are presently under investigation in several electron laboratories. The comparison of the theoretical results with experiment for several kinematical conditions and diverse channels can serve to learn about different physical processes occurring in the reaction. The potential of this theoretical tool to make prospections for possible experiments, aiming at pinning down certain reaction probabilities, is also emphasized.  相似文献   

2.
《Physics letters. [Part B]》1987,191(3):227-231
Calculations of charge-exchange processes in the final state of the quasi-elastic (e, e′N) reaction have been performed employing the Lane formalism. The Lane equations were decoupled by means of a transformation to the isospin representation. It is found that charge exchange has a small effect on the (e, e′p) cross section, but may play an appreciable role in the (e, e′n) reaction.  相似文献   

3.
Reaction microscope is a powerful tool for studying ion-atom/molecule dynamics, it can also be employed to investigate electron impact ionization processes. Traditionally these processes are studied by using the (e, 2e) or (e, 3e) techniques, most data are collected for single ionization and for very small scattering angles, i.e. (e, 2e), experimental data of double ionization (e, 3e)[1] and multiple ionization are scarce, because in most cases the efficiencies (mainly determined by solid angles) are extremely small for (e, 3e) processes, about 10^-7~10^-9. On the other hand, the new technique-reaction microscope can detect mutli-fragments in one collision with very  相似文献   

4.
Recent progress of(e,2e)spectroscopy,or Electron Momentum Spectros-copy(EMS),on laser excited oriented atoms,large bio-organic moleculesand thin films is reviewed.  相似文献   

5.
《Nuclear Physics A》1997,615(3):373-390
Exclusive cross sections of the 16O(e,e′pp) 14C knockout reaction are calculated for transitions to the low-lying discrete final states of the residual nucleus. Short-range correlations and two-body currents, due to the excitation of a Δ resonance in the intermediate state, are included in the calculations. Final-state interactions are taken into account by means of phenomenological spin-dependent optical potentials. Recoil-momentum distributions for transitions to states with different angular momentum exhibit different shapes, which are basically determined by the cm orbital angular momentum of the initial proton pair.  相似文献   

6.
This paper reports on measurements of the 3He(e,epp) reaction measured at AmPS and the 3He(e,epn) reaction measured at MAMI. The measurements were performed in similar kinematics to allow a comparison to be made between the cross sections of the two reactions. Results are shown for both reactions together with a comparison for the 3He(e,epp) data with continuum Faddeev calculations.  相似文献   

7.
将文献[8]发展的(e,2e)反应多重散射理论推广到更一般的情况,去掉不动点近似。用得到的波函数进行了计算,并与文献[9]的结果做了比较。  相似文献   

8.
尚仁成  马骏 《物理学进展》1998,18(4):369-382
传统(e,2e)谱学已成为研究原子和分子电子结构和电离机制的强有力工具之一,本文首先简要回顾了迄今国内外传统(e,2e)谱学研究的历史和现状。然后,再重点介绍近几年开展极化(e,2e)碰撞电离研究的进展。  相似文献   

9.
This poster presentation is intended to show preliminary results from calculations of the inclusive (e,e′) transverse response functions of 4He. Up to now we have only included the E1 and M1 multipoles and therefore no comparison with experiment is shown. That will be done once all relevant multipoles have been calculated. Details of the calculation are summarized in the text below.  相似文献   

10.
传统(e,2e)谱学已成为研究原子和分子电子结构和电离机制的强有力工具之一,本文首先简要回顾了迄今国内外传统(e,2e)谱学研究的历史和现状。然后,再重点介绍近几年开展极化(e,2e)碰撞电离研究的进展。  相似文献   

11.
《Nuclear Physics A》1997,625(3):513-520
Multistep direct scattering of the ejectile proton is considered in (e,e′p) reactions in the quasi-free region as an improvement over the usual treatment of final-state interactions by means of an optical potential. The theory is applied to 40Ca(e,e′p) as a case example. Important contributions of two- and three-step processes are found at high missing energy and momentum in agreement with the experimental trend.  相似文献   

12.
将氢原子的(e,2e)碰撞的多重散射展开理论进一步推广,使之适用于复杂原子的(e,2e)碰撞。 关键词:  相似文献   

13.
(e,2e)的多重散射展开方法   总被引:1,自引:0,他引:1       下载免费PDF全文
陈学俊  郑良友 《物理学报》1991,40(10):1595-1600
本文将作者之一在文献[6]中发展的多重散射展开方法应用于氢原子(e,2e)的三重微分截面的计算。具体地得出Ehrhard几何条件下的数值结果,所得结果与实验数据符合得相当好。  相似文献   

14.
利用修正的BBK理论模型,在共面,等能分享,固定相对角度几何条件下,计算了能量分别为58.4,68,81.6,108.8和174.4eV的入射电子碰撞He+(1s)(e,2e)反应三重微分截面(TDCS),并讨论了交换,关联与干涉效应及入射道库仑场对TDCS的影响。结果表明,这些效应对决定TDCS的角度分布及大小是非常重要的。  相似文献   

15.
低能氢原子(e, 2e)反应中的电子关联   总被引:3,自引:3,他引:0  
利用能壳上跃迁矩阵元的后滞形式和双势公式,计算了入射能为54.4 eV时,电子入射单离化氢原子的三重微分截面(TDCS),并与实验数据、BBK理论和DS3C理论结果进行了比较.通过分解动能算符,对快电子采用平面波的近似,散射振幅可以表示成结构因子(T2)和关联因子(T12)乘积的形式,在略去前者中电子质心运动的基础上,通过对后者中求和级数的讨论,指出了T12中电子的质心运动和相对运动对TDCS的影响,从而分析了T12的收敛问题.  相似文献   

16.
极化电子在(e,2e)散射中的应用   总被引:2,自引:0,他引:2  
介绍了用极化电子进行(e,2e)散射的意义及其当前国际上的进展,然后对正在研制的一台(e,2e)谱仪进行了介绍,包括其总体结构及关键部分的特色,其中着重讨论了一种光学极化仪.  相似文献   

17.
《Nuclear Physics A》1987,475(4):687-719
The proton spectral function has experimentally been determined with the 3He(e, e′p) reaction for missing energies, 0<Em<70MeV, and recoil momenta, 0<PB<310 MeV/c. Experimental results are obtained for both the two-body, 3He(e, e′p)2H, and three-body breakup processes. Proton momentum density distributions, obtained in a PWIA analysis, are compared with theoretical calculations: Faddeev solutions with the RSC and Paris potentials, and variational calculations with various potentials, including those with a three-nucleon interaction term. Energy-weighted sum rule results are presented and compared with theoretical predictions. The coincidence cross sections are also compared with calculations which include the effects of final state interactions and meson exchange currents. Consistency of the results with PWIA is investigated in the framework of the Chew-Low extrapolation procedure.  相似文献   

18.
低能(e,2e)反应中的卢瑟福散射效应   总被引:1,自引:0,他引:1  
以入射能量为64.6eV、能量均分、共面不对称几何条件下He原子电子碰撞电离过程为例,分析低能(e,2e)反应中的碰撞机制、交换效应和卢瑟福散射效应,揭示了两种新的碰撞机制(DB碰撞和TB碰撞)的物理实质。  相似文献   

19.
We discuss production and decays of stops, sbottoms, -sneutrinos, and staus in e+e annihilation in the energy range s = 0.5-1TeV. We present numerical predictions within the Minimal Supersymmetric Standard Model for cross sections and decay rates, including one-loop radiative corrections as well as initial state radiation. We also study the importance of beam polarization for the determination of the underlying SUSY parameters. Moreover, we make a comparison of the potential to study squarks and sleptons of the 3rd generation between Tevatron, LHC, and Linear Collider.  相似文献   

20.
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   

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