Calculating the energy loss of leading jets

TL;DR

This paper proposes a method for directly measuring the energy loss of leading jets using a perturbative calculation at NLL' accuracy, emphasizing the importance of specific criteria and observables for accurate measurement.

Contribution

It introduces a framework for direct jet energy loss measurement at the cross section level, combining perturbative calculations with criteria for observable selection.

Findings

Numerical results demonstrate the feasibility of the proposed measurement approach.

Identification of criteria necessary for accurate jet energy loss measurement.

Inclusion of threshold corrections enhances the precision of the predictions.

Abstract

The energy loss mechanism of jets plays a central role in nuclear and high energy physics. We propose direct measurements of the energy loss of leading jets and perform a calculation at next-to-leading logarithmic (NLL$'$) accuracy in the vacuum. The formation of leading jets can be described by jet functions which constitute probability densities and thus allow for a perturbative calculation of the average the energy loss. We identify the following three criteria for a direct measurement of jet energy loss at the cross section level. $i)$ We measure a well defined object, the leading jet, where the formation process can be expressed in terms of a probability density. $ii)$ In addition, we need a measurement of a hard reference scale with respect to which jet energy loss is defined. $iii)$ At leading logarithmic accuracy, we require that the jet energy loss can be identified with parton energy loss. We discuss suitable observables and present numerical results including threshold corrections by making use of a parton shower Monte Carlo approach.