标题： 解决深度虚拟康普顿散射中运动学歧义的QCD预测 显示英文标题

标题： Resolving kinematic ambiguities in QCD predictions for Deeply Virtual Compton Scattering

摘要： 现有的量子色动力学（QCD）对深度虚拟康普顿散射（DVCS）的预测依赖于偏斜参数的约定以及用于定义自旋振幅的参考系。 这些歧义在形式上是幂次抑制的，但数值上是显著的。 它们被最近计算到$1/Q^2$精度的有限-$t$和靶质量修正所抵消。 结果表明，至少对于非极化观测量，通过选择一个由光子动量定义纵向方向的特定参考系，可以最小化这些修正。 显示英文摘要

摘要： The existing QCD predictions for the Deeply Virtual Compton Scattering (DVCS) depend on the convention used for the skewedness parameter and on the reference frame used to define helicity amplitudes. These ambiquities are formally power-suppressed but numerically significant. They are cancelled by finite-$t$ and target mass corrections that have been calculated recently to the $1/Q^2$ accuracy. It turns out that these corrections can be minimized, at least for unpolarized observables, by choosing a specific reference frame where longitudinal directions are defined by the photon momenta.