论文标题
分析性的两回路振幅，价格为$ TW $生产：领先的颜色和光线环贡献
Analytic two-loop amplitudes for $tW$ production: leading color and light fermion-loop contributions
论文作者
论文摘要
我们介绍了HADRONIC $ TW $生产的两环振幅的分析结果，重点是领先的颜色和光线效果。使用规范微分方程的方法进行双环积分的计算。结果是用多个小聚集体表示的，并通过将红外差异与异常维度的预测进行比较来检查。结合我们先前计算的一环平方幅度，我们获得了与NNLO Monte Carlo计算相关的硬函数。我们发现，在顶部夸克速度较小的区域中，硬函数的变化缓慢，但在该区域的顶部夸克速度非常大。相后空间集成后，领先的颜色硬函数可为领先订单横截面的$ 5.4 \％$校正，而光费米循环的贡献约为$ -1.4 \％$。
We present the analytical results of the two-loop amplitudes for hadronic $tW$ production, focusing on the leading color and light fermion-loop contributions. The calculation of the two-loop integrals is performed using the method of canonical differential equations. The results have been expressed in terms of multiple polylogarithms and checked by comparing the infra-red divergences with the predictions from anomalous dimensions. Combined with the one-loop squared amplitudes we have computed previously, we obtain the hard function relevant to a NNLO Monte Carlo calculation. We find that the hard function varies slowly in the region with small top quark velocity but increases dramatically in the region with very large top quark velocity. After phase space integration, the leading color hard function gives an about $5.4\%$ correction to the leading order cross section, while the light fermion loop contributes about $-1.4\%$.
