论文标题
DVCS的两环系数函数：矢量贡献
Two-loop coefficient function for DVCS: Vector contributions
论文作者
论文摘要
使用基于共形对称性的方法，我们计算了对矢量味道非单词对深层comptual compton散射（DVC）的贡献的两环系数函数。在$ \ overline {\ text {ms}} $方案中，介绍了动量分数空间中系数函数的分析表达式。对于普通顿分布的简单模型而言，相应的近临界订单校正到康普顿形式$ \ MATHCAL {H} $似乎很大：一个比近代领先的订单校正小的两个因子，大约$ \ sim 10 $ \ \ sim 10 $ \％的树水平在$ q^$ q^2 = 4 $ q^2 = 2 = 4 $ q^2 = 4 $ g^2 = 2 = 4 $ g^2 = 2 = 2 = 2 = 2 = 2 = 2 = 2 = 2 = 2 = 4 $ g
Using the approach based on conformal symmetry we calculate the two-loop coefficient function for the vector flavor-nonsinglet contribution to deeply-virtual Compton scattering (DVCS). The analytic expression for the coefficient function in momentum fraction space is presented in the $\overline{\text{MS}}$ scheme. The corresponding next-to-next-to-leading order correction to the Compton form factor $\mathcal{H}$ for a simple model of the generalized parton distribution appears to be rather large: a factor two smaller than the next-to-leading order correction, approximately $\sim 10$\% of the tree level result in the bulk of the kinematic range, for $Q^2=4$ GeV$^2$.
