论文标题
通过具有较大不变质量的光子 - 膜对的独家光生生启动来访问GPD
Accessing GPDs through the exclusive photoproduction of a photon-meson pair with a large invariant mass
论文作者
论文摘要
我们研究了在QCD分解框架中工作的光子 - 膜对的独家光生生成。明确地，我们考虑了最终状态下的$ρ$ -Meson或收费的$π$。此过程可访问手性含量的GPD以及手性odd GPD。我们在这里专注于手性的领域。计算以领先顺序和领先扭曲进行。我们讨论了在各种实验中测量它们的前景，例如JLAB 12-GEV，Compass，Future EIC和LHC（在超疗法碰撞中）。特别是，在对撞机实验中可用的高质量能量可用于探测小偏度$ξ$的GPD。我们还计算相对于传入光子的极化不对称。还将替代分布幅度（“全息”形式）的结果与渐近分布幅度获得的预测进行了比较。
We study the exclusive photoproduction of a photon-meson pair with a large invariant mass, working in the QCD factorisation framework. Explicitly, we consider a $ ρ$-meson or a charged $ π$ in the final state. This process gives access to chiral-even GPDs as well as chiral-odd GPDs. We focus here on the chiral-even sector. The computation is performed at leading order and leading twist. We discuss the prospects of measuring them in various experiments such as JLab 12-GeV, COMPASS, future EIC and LHC (in ultraperipheral collisions). In particular, the high centre of mass energies available at collider experiments can be used to probe GPDs at small skewness $ ξ$. We also compute the polarisation asymmetries with respect to the incoming photon. The results for an alternative distribution amplitude (`holographic' form) are also compared with the predictions obtained with an asymptotic distribution amplitude.
