Vector meson dominance and deep inelastic scattering at low and medium Q squared
Vector meson dominance and deep inelastic scattering at low and medium Q squared
复制标题
低和中 Q 平方下的矢量介子优势和深度非弹性散射
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
B. Mangazeev
中科院分区：
文献类型：
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作者：
E. Bugaev;B. Mangazeev
我们认为，深非弹性散射（DIS）在小值的Q平方是一个基本上非微扰的过程，可以描述，至少部分地，矢量介子优势（VMD）模型。我们通过简单的计算表明，在Q的平方<1GeV的平方的范围内，VMD模型可以成功地解释在x（5e-2 - 1 e-4）的宽区间内DIS结构函数的数据.为了描述更大Q平方的数据，我们使用了两分量（VMD +微扰QCD）方法。我们表明，这两个组件可以分离，如果VMD是用于对齐喷射版本。在计算结构函数的VMD分量时，我们考虑了ρ介子的激发态和ρ介子家族不同成员之间的非对角跃迁。这些转变的振幅得到使用的光前Bethe-Salpeter方程的形式主义和衍射散射本征态的方法。微扰QCD分量的计算采用色偶极模型的框架，偶极截面具有Regge型能量依赖性。我们提出了我们的预测与实验数据的核子结构函数的详细比较的结果。我们也得到了近似预测的结构函数在该地区的非常小的x，高达1 e-9，并表明，非微扰分量在这样的值的x仍然是相对较大的，必须考虑到，如果Q平方约几个GeV的平方或更小。
We argued that deep inelastic scattering (DIS) at small values of Q squared is an essentially nonperturbative process and can be described, partially at least, by the vector meson dominance (VMD) model. We showed by the straightforward calculation that VMD model alone can successfully explain data on structure functions of DIS in a broad interval of x (5e-2 - 1e-4) for the region Q squared < 1 GeV squared. For a description of data at larger Q squared we used the two-component (VMD + perturbative QCD) approach. We showed that these two components can be separated if VMD is used in the aligned jet version. We took into account, in calculations of VMD component of structure functions, the excited states of the rho-meson and nondiagonal transitions between different members of the rho-meson family. Amplitudes of these transitions were obtained using a formalism of the light-front Bethe-Salpeter equation and the method of diffraction-scattering eigenstates. The perturbative QCD component was calculated using a framework of the colour dipole model with the dipole cross section having a Regge-type energy dependence. We presented results of the detailed comparison of our predictions with experimental data for structure functions of the nucleon. We obtained also approximate predictions for the structure functions in the region of very small x, up to 1e-9, and showed that nonperturbative component at such values of x is still relatively large and must be taken into account if Q squared is about few GeV squared or less.