Investigation of the factorization scheme dependence of finite order perturbative QCD calculations: searching for approximately ZERO factorization scheme

TL;DR

This paper explores the dependence of finite order perturbative QCD calculations on the factorization scheme, aiming to identify an approximately zero scheme that improves NLO Monte Carlo event generators.

Contribution

It investigates the feasibility of using a factorization scheme close to ZERO for NLO calculations across all relevant x ranges in QCD phenomenology.

Findings

ZERO scheme has limited practical applicability.

A search for a more applicable scheme close to ZERO is conducted.

The study assesses the scheme dependence of NLO splitting functions.

Abstract

The possibility of an improvement of current NLO Monte Carlo event generators by means of choosing a suitable factorization scheme is studied. The optimal factorization scheme for combining initial state parton showers and NLO hard scattering cross-sections is the ZERO factorization scheme, in which all NLO splitting functions vanish. However, it has turned out that the ZERO factorization scheme has a limited range of practical applicability. Hence, this paper is focused on searching for a factorization scheme which is applicable at the NLO in the full range of x relevant for QCD phenomenology and simultaneously close to the ZERO factorization scheme (i.e. the corresponding NLO splitting functions are close to zero).