论文标题
前阶QED辐射校正质子上的临时康普顿散射
Leading-order QED radiative corrections to timelike Compton scattering on the proton
论文作者
论文摘要
我们评估了对时间层康普顿散射（TCS）过程$γp\ to l^ - l^+ p $的前阶Q辐射校正。我们使用不同模型的TCS振幅研究了两个能源制度中的这些校正。在低能策略中，我们计算了由于质子及其最低能量激发$δ（1232）$共振引起的贡献。在高能接近运动的运动方案中，我们根据通用Parton分布（GPD）计算手提包方法中的TCS振幅。在横截面的水平上，我们发现QED辐射校正在低能制度的$ 5 -10 \％$范围内，高能制度的$ 20 \％$。我们表明，在di-lepton前后不对称以及光子束螺旋不对称中，这些校正几乎取消了，使它们呈金镀金可观察到，以提取TCS振幅的真实和虚构部分。我们特别证明了这些不对称性对GPD参数化的敏感性对于最近的CLAS12@JLAB TCS实验。
We evaluate the leading-order QED radiative corrections to the timelike Compton scattering (TCS) process $γp \to l^- l^+ p$. We study these corrections in two energy regimes using different models for the TCS amplitude. In the low-energy regime we calculate the contribution due to the proton and its lowest-energy excitation, the $Δ(1232)$ resonance. In the high-energy near-forward kinematical regime we calculate the TCS amplitude in a handbag approach in terms of Generalized Parton Distributions (GPDs). On the level of cross sections we find the QED radiative corrections to be in the $5 -10\%$ range in the low-energy regime and around $20\%$ in the high-energy regime. We show that in both the di-lepton forward-backward asymmetry as well as in the photon beam helicity asymmetry these corrections nearly cancel out, making them gold-plated observables to extract the real and imaginary parts of the TCS amplitude. We demonstrate in particular the sensitivity of these asymmetries on GPD parameterizations for a recent CLAS12@JLab TCS experiment.
