论文标题
在Pion-Nucleon碰撞中独家生产一对高横向动量光子，用于提取广义Parton分布
Exclusive production of a pair of high transverse momentum photons in pion-nucleon collisions for extracting generalized parton distributions
论文作者
论文摘要
我们表明，如果光子的横向动量$ Q_T $相对于碰撞pion，则可以系统地研究在Pion-Nucleon碰撞中的一对高横向动量光子的独家产生。我们证明，对该专有过程的散射幅度的领先功率非扰动贡献是无关的，并且可以系统地分解为通用Pion的分布振幅（DAS）和Nucleon的广义Parton分布（GPD），这些分布（GPDS）与相应的安全性安全和特殊性的简短零件相应地卷积。 $ 1/q_t $的功率抑制了对此分解表达式的校正。我们定量地证明，这种新型的独家过程不仅与提取GPD的现有过程相辅相成，而且还能够增强对DAS和GPD对活动零件的依赖性的敏感性。我们还介绍了其他类型的独家观测值，以增强我们探索GPD的能力，尤其是它们的$ x $依赖性。
We show that exclusive production of a pair of high transverse momentum photons in pion-nucleon collisions can be systematically studied in QCD factorization approach if the photon's transverse momentum $q_T$ with respect to the colliding pion is much greater than $Λ_{\rm QCD}$. We demonstrate that the leading power non-perturbative contributions to the scattering amplitudes of this exclusive process are process-independent and can be systematically factorized into universal pion's distribution amplitudes (DAs) and nucleon's generalized parton distributions (GPDs), which are convoluted with corresponding infrared safe and perturbatively calculable short-distance hard parts. The correction to this factorized expression is suppressed by powers of $1/q_T$. We demonstrate quantitatively that this new type of exclusive processes is not only complementary to existing processes for extracting GPDs, but also capable of providing an enhanced sensitivity to the dependence of both DAs and GPDs on the active parton's momentum fraction $x$. We also introduce additional, but the same type of exclusive observables to enhance our capability to explore GPDs, in particular, their $x$-dependence.
