论文标题

curci-Ferrari模型的幽灵 - 抗恒星 - 格鲁恩顶点:两循环校正

The ghost-antighost-gluon vertex from the Curci-Ferrari model: Two-loop corrections

论文作者

Barrios, Nahuel, Peláez, Marcela, Reinosa, Urko, Wschebor, Nicolás

论文摘要

已显示curci-ferrari模型可以很好地掌握Landau仪表的纯Yang-mills相关函数,该函数已经按单层阶。在最近的一项工作中,通过评估对Gluon和Ghost Expagors的两环校正来测试这些结果的鲁棒性。我们通过在特定的运动学配置中计算出相同的精度来实现这种系统研究,从而使计算变得更加简单。由于模型的参数和字段的正常化都已经固定在先前的工作中,因此本计算既代表了纯预测,又代表了该方法的严格测试。我们发现,与早期的一环结果相比,两循环结果系统地改善了与蒙特卡洛模拟的比较。在SU($ 3 $)的情况下,改进尤其有意义,在这种情况下,预测的幽灵 - 抗恒星顶点与数据非常吻合。但是,SU中的比较($ 2 $)的情况并不那么好。这可能是由于在这种情况下在红外存在较大的耦合常数所致,尽管我们注意到在非扰动连续性方法中已经引用了类似的不匹配。尽管SU($ 2 $)的情况有这些功能,但仍有可能找到一组拟合传播器和幽灵 - 抗恒定螺旋体顶点的参数,以合理的精度。

The Curci-Ferrari model has been shown to provide a good grasp on pure Yang-Mills correlation functions in the Landau gauge, already at one-loop order. In a recent work, the robustness of these results has been tested by evaluating the two-loop corrections to the gluon and ghost propagators. We pursue this systematic investigation by computing the ghost-antighost-gluon vertex to the same accuracy in a particular kinematic configuration that makes the calculations simpler. Because both the parameters of the model and the normalizations of the fields have already been fixed in a previous work, the present calculation represents both a pure prediction and a stringent test of the approach. We find that the two-loop results systematically improve the comparison to Monte-Carlo simulations as compared to earlier one-loop results. The improvement is particularly significative in the SU($3$) case where the predicted ghost-antighost-gluon vertex is in very good agreement with the data. The same comparison in the SU($2$) case is not as good, however. This may be due to the presence of a larger coupling constant in the infrared in that case although we note that a similar mismatch has been quoted in non-perturbative continuum approaches. Despite these features of the SU($2$) case, it is possible to find sets of parameters fitting both the propagators and the ghost-antighost-gluon vertex to a reasonable accuracy.

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