Determination of HQET nonperturbative matrix elements with renormalon subtraction using Fourier transform

TL;DR

This paper introduces a Fourier transform-based renormalon subtraction method to nonperturbatively determine HQET matrix elements, addressing the renormalon problem in QCD calculations.

Contribution

It presents the first method to subtract the $u=1$ renormalon for accurate HQET matrix element determination using Fourier transform.

Findings

Successfully determined $ar{ ext{Lambda}}$ and $mbda_{}^2$ matrix elements.

First application of $u=1$ renormalon subtraction in this context.

Provides a systematic approach to incorporate nonperturbative effects in QCD.

Abstract

As higher order perturbative series are available, it is becoming necessary to include nonperturbative effects in QCD calculations using the OPE. In order to systematically determine nonperturbative effects and to incorporate them into theoretical calculations, the renormalon problem should be resolved. We use a renormalon subtraction method utilizing Fourier transform to determine nonperturbative matrix elements of HQET, $\bar{\Lambda}$ and $\mu_{\pi}^2$. This is the first determination performed with subtraction of the $u=1$ renormalon.