论文标题
来自Curci-Ferrari模型及其领先的红外行为的两环三绿色顶点到所有循环订单
Two-loop three-gluon vertex from the Curci-Ferrari model and its leading infrared behavior to all loop orders
论文作者
论文摘要
我们以两环秩序在Curci-Ferrari（CF）模型中使用一个消失的外部动量评估三元素顶点，并将我们的结果与SU（2）和SU（2）和SU（2）和SU（3）组的Landau-gauge晶格模拟进行了比较。通过将两点函数拟合到晶格数据来调整模型的参数，我们对三束顶点的评估是作为纯预测而产生的。我们发现，与早期的一环计算相比，两循环校正系统地改善了模型和晶格数据之间的一致性，在SU（3）情况下，具有更好的一致性，如先前的研究[1,2]。我们还分析了我们计算的重新归一化方案依赖性。在所有情况下，当包括两环校正时，这种依赖性都会减少，这与扰动CF范式一致。此外，我们研究了三度顶点的低动量状态，与零交叉的可能性有关。在CF模型中，我们表明，确切顶点的领先红外行为是由以一环秩序产生的线性对数给出的，乘以所有订单在零momentum处的立方体幽灵敷料函数（我们为其他顶点功能提供了相似的精确结果）。我们认为，在FP框架中，该属性仍然是真实的。这表明零交叉是精确的三胶顶点函数的属性。然而，在CF模型中，我们发现零交叉的比例从一单循环到两循环时会大大降低。这似乎与最近的一些晶格模拟一致[3]。我们的分析还使我们能够支持有关树级张量组件的主导地位的最新主张[4]。
We evaluate the three-gluon vertex with one vanishing external momentum within the Curci-Ferrari (CF) model at two-loop order and compare our results to Landau-gauge lattice simulations of the same vertex function for the SU(2) and SU(3) gauge groups in four dimensions. The parameters of the model being adjusted by fitting the two-point functions to lattice data, our evaluation of the three-gluon vertex arises as a pure prediction. We find that two-loop corrections systematically improve the agreement between the model and the lattice data as compared to earlier one-loop calculations, with a better agreement in the SU(3) case, as already seen in previous studies [1,2]. We also analyze the renormalization scheme dependence of our calculation. In all cases, this dependence diminishes when two-loop corrections are included, which is consistent with the perturbative CF paradigm. In addition, we study the low momentum regime of the three-gluon vertex in relation with the possibility of zero-crossing. Within the CF model, we show that the leading infrared behavior of the exact vertex is given by the same linear logarithm that arises at one-loop order, multiplied by the all orders cubic ghost dressing function at zero-momentum (we provide similar exact results for other vertex functions). We argue that this property remains true within the FP framework under the assumption that the resummed gluon propagator features a decoupling behavior. This shows that the zero-crossing is a property of the exact three-gluon vertex function. Within the CF model, we find however that the scale of the zero-crossing is considerably reduced when going from one- to two-loop order. This seems consistent with some recent lattice simulations [3]. Our analysis also allows us to support recent claims about the dominance of the tree-level tensor component [4].
