Study of a few-nucleon system using electron scattering (relativistic effects, meson exchange effects, contributions of quarks)

1.我们完成了<40>东北大学的^ Ca（e，e 'p）实验的研究，并将其与先前研究的^<12>C和^<16>0的结果进行了比较。实验获得的截面几乎一半的理论上得到的使用相对论DWIA计算的所有目标。这一结果表明，计算中遗漏了一些重要的成分。介子交换流的贡献对12 C核最大，对重核的贡献变小.在麻省理工学院贝茨分校进行的四动量转移为Q^2 = 0.33（GeV/c）^2的虚光子康普顿散射实验中，得到的质子极化率在使用低能展开和使用色散关系分析的值之间存在很大差异。这种差异在较高的动量转移中是看不到的。在MIT-Bates和JLab用色散理论得到的偶极子参数是一致的，但与 ...更多信息 在美因茨获得的值。我们分析了JLab的^3He（e，e 'p）实验数据，并将结果发表在《物理评论快报》上。我们将^3He中质子的动量分布与用各种波函数计算的结果进行了比较，发现在1 GeV/c附近，计算结果与实验结果不一致。这表明核子以外的自由度是描述原子核所必需的.我们制作了一个兰姆位移型偏振计，并对其性能进行了测试。利用旋光仪直接测量了氘核的三个磁子能级的分数。我们在京都大学的电子储存环中进行了使用自约束离子靶的电子散射测试实验。该靶利用电子束诱导的静电场捕获正原子离子。捕获的离子的条件由分析仪系统监测，该分析仪系统观察提取的离子的电荷状态分布。我们已经证实铯离子实际上被困在目标中。我们还评估了使用安装在目标区域的线靶的散射电子探测系统的性能。少

1. We have completed the study of ^<40>Ca(e, e'p) experiment made at Tohoku University, and compared it with previously studied results of ^<12>C and ^<16>0. The experimentally-obtained cross sections were almost half of theoretically obtained ones using relativistic DWIA calculations for all targets. This result suggests that some important ingredients are missing in the calculation. The contribution of the meson exchange currents is largest for 12C, and becomes smaller for heavier nuclei.2. Polarizabilities of the proton obtained from an experiment of virtual-photon Compton scattering made at a four-momentum transfer of Q^2 = 0.33 (GeV/c)^2 at MIT-Bates are much different from each other between the values that were analyzed using the low energy expansion and using dispersion relation. Such a discrepancy is not seen at higher momentum-transfers. The dipole parameters obtained at MIT-Bates and at JLab using the dispersion theory are consistent each other, but different very much from … More the value obtained at Mainz.3. We have analyzed data of the ^3He(e, e'p) experiment made at JLab, and published the result on Physical Review Letters. We compared the momentum distribution of protons in ^3He with calculations using various wave functions, and found no calculations agree with the experimental result near 1 GeV/c. It suggests that degrees of freedom beyond nucleons are needed for description of nuclei.4. We have fabricated a Lamb-shift type polarimeter and tested its performance. The fraction of three magnetic sub-levels of the deuteron was directly measured using the polarimeter.5. We have performed test experiments of electron scattering using a self-confining ion target in an electron storage ring at Kyoto University. This target traps positive atomic ions using electrostatic field induced by an electron beam. The condition of trapped ions was monitored by an analyzer system, which observed charge-state distribution of extracted ions. We have confirmed Cs ions were actually trapped in the target. We also evaluated the performance of the scattered-electron detection system using wire targets installed in the target region. Less