高Q^2电子原子核单举准弹性散射截面的计算方法

A Calculation Method of Inclusive Electron Nucleus Quasi-elastic Scattering Cross Section at High Q^2

电子与原子核碰撞实验是通过中高能探针探测原子核结构的方法。本文提供了一个高Q^2单举准弹性电子原子核散射截面的计算方法,此方法是基于核子-核子短程关联的经验公式与弱束缚近似下的氘核散射截面模型。在弱束缚近似下,氘核可以看成是由近似自由质子与中子组成,质子与中子的短程关联可以忽略,氘核结构函数可以写成质子与中子结构函数线性组合,从而可以得到氘核的散射截面。根据氘核散射截面以及短程关联的经验公式,可以得到考虑短程关联的原子核A>2的散射截面。我们将计算得到的散射截面与已有的实验和及Bosted拟合方法的结果比较,发现本文的方法在大x和Q^2>2 GeV^2区域得到的结果与实验结果符合得较好并且对于一些重原子核,尤其是~4He核,明显优于Bosted方法的结果。

The electron nucleus collision experiments are approaches measuring the structure of nuclei by using intermediate and high energy probe. This paper shows a calculation method of inclusive electron nucleus quasielastic scattering cross section at high Q2 which based on a empirical formula of Nucleon-Nucleon Short Range Correlation（NN-SRC） and a model of electron deuteron quasi-elastic cross section in Weak-Binding Approximation（WBA）. In WBA, the deuteron can be regarded as the combination of quasi-free proton and neutron and the short range correlation between them can be ignored. Therefore the structure function of deuteron can be written as the linear combination of that of proton and neutron, then one can get the cross section of deuteron. According to the cross section of deuteron and the empirical formula, one can obtain the cross section of nuclei A 2 which considers NN-SRC effect. We compare our calculation results with existing experiments and the results calculated by Bosted＇ fit method, then find that our results match the experiments at high x and Q2 2GeV2 and better significantly than the Bosted＇s results for some heavier nucleus, especially 4He.