A new reduction strategy for special negative sectors of planar two-loop integrals without Laporta algorithm

Abstract

In planar two-loop integrals there is a dedicated sector such that when its index is zero, the two-loop integral decomposes into the product of two one-loop integrals. We show an alternative reduction strategy for these sectors when their index is negative using the Baikov representation. This reduction strategy is free from the Laporta algorithm. It follows a top-down approach and is much faster than approaches based on the brute-force, conventional integration by parts identities.