Towards regularized higher-order computations in QFT without DREG

TL;DR

This paper discusses a novel approach to higher-order quantum field theory calculations that avoids dimensional regularization by using the loop-tree duality theorem, enabling finite computations directly in four dimensions.

Contribution

It introduces a regularization method based on loop-tree duality that simplifies higher-order computations without DREG, applicable to physical processes.

Findings

Successfully applied to benchmark processes

Handles infrared and ultraviolet divergences in 4D

Produces finite results without dimensional regularization

Abstract

In this talk, we review the basis of the loop-tree duality theorem, which allows to rewrite loop scattering amplitudes in terms of tree-level like objects. Since the loop measure is converted into a phase-space one, both virtual and real contributions are expressible using the same integration variables. A physically motivated momentum mapping allows to generate the real emission process starting from the Born kinematics and the loop momenta. The integrand-level combination leads to regular functions, which can be integrated without using dimensional regularization (DREG) and correctly reproduce the finite higher-order corrections to physical observables. We explain the implementation of this novel approach to compute some benchmark physical processes, and we show how to deal with both infrared and ultraviolet divergences in four space-time dimensions.