论文标题
在深层虚拟康普顿散射中的手性和痕迹异常
Chiral and trace anomalies in Deeply Virtual Compton Scattering
论文作者
论文摘要
受塔拉索夫（Tarasov）和维纳格巴兰（Venugopalan）的最新工作的启发，我们通过引入非前方动量$ l^μ$作为红外调节器来计算与极化和非极化深度弹性散射（DIS）相关的单环夸克盒图。在极化情况下，我们将杆$ 1/l^2 $重新等级与轴向（手性）异常有关。此外，我们获得了通常的对数项和dis系数函数。我们根据广义的Parton发行量（GPD）$ \ tilde {h} $和$ \ tilde {e} $来解释结果，并讨论了Compton散射幅度的QCD分解可能违反。值得注意的是，我们还发现在非极化情况下是痕量异常的残留物。我们认为，这些杆子被GPDS $ H $和$ E $的可能的无质量粘合球杆取消，以及在它们的瞬间，Nucleon Reveratiation Formation formational formation formation $ a，b $ a，b $和$ d $。该机制阐明了重力形式与Gluon冷凝物操作员$ f^{μν} f_ {μν} $之间的连接。
Inspired by recent work by Tarasov and Venugopalan, we calculate the one-loop quark box diagrams relevant to polarized and unpolarized Deep Inelastic Scattering (DIS) by introducing off-forward momentum $l^μ$ as an infrared regulator. In the polarized case, we rederive the pole $1/l^2$ related to the axial (chiral) anomaly. In addition, we obtain the usual logarithmic term and the DIS coefficient function. We interpret the result in terms of the generalized parton distributions (GPDs) $\tilde{H}$ and $\tilde{E}$ and discuss the possible violation of QCD factorization for the Compton scattering amplitude. Remarkably, we also find poles in the unpolarized case which are remnants of the trace anomaly. We argue that these poles are cancelled by the would-be massless glueball poles in the GPDs $H$ and $E$ as well as in their moments, the nucleon gravitational form factors $A,B$ and $D$. This mechanism sheds light on the connection between the gravitational form factors and the gluon condensate operator $F^{μν}F_{μν}$.
