Multiloop corrections for collider processes using auxiliary mass flow

Abstract

With a key improvement, the auxiliary mass flow method is now able to compute Feynman integrals encountered in cutting-edge collider processes. We have successfully applied it to compute some integrals involved in two-loop electroweak corrections to $e^+e^-\to HZ$, two-loop QCD corrections to $3j$, $W/Z/H+2j$, $t\bar{t}H$ and $4j$ production at hadron colliders, and three-loop QCD corrections to $t\bar{t}$ production at hadron colliders, all of which are crucial for precision frontier in collider physics in the following decade. Our results are important building blocks and benchmarks for future studies of these processes.

Figures (4)

• Figure 1: Massless two-loop double-pentagon Feynman diagram.
• Figure 2: Nonfactorized MIs for single-mass vacuum integrals up to three loops. The solid curves represent massive propagators and dashed curves represent massless propagators.
• Figure 3: The all-small region iteration of massless two-loop double-pentagon in "propagator" mode. Solid lines mean propagators with $\eta$. The number of master integrals before and after introducing $\eta$ are shown under each diagram, except the last one.
• Figure 4: Some topologies involved in cutting-edge processes. Massless particles and massive particles are denoted as dashed lines and solid lines, respectively.