Anti-$k_T$ jet function at next-to-next-to-leading order

TL;DR

This paper develops a method to compute jet functions at higher orders in QCD, specifically for anti-$k_T$ jets, enhancing the precision of theoretical predictions in jet physics.

Contribution

It introduces a sector decomposition method with soft subtractions to evaluate jet functions at NNLO, demonstrated on anti-$k_T$ jet functions.

Findings

Successfully computed the anti-$k_T$ jet function at NNLO.

Provides a new approach to higher-order jet function calculations.

Enhances theoretical accuracy for jet-based measurements.

Abstract

Jets constructed via clustering algorithms (e.g., anti-$k_T$, soft-drop) have been proposed for many precision measurements, such as the strong coupling $\alpha_s$ and the nucleon intrinsic dynamics. However, the theoretical accuracy is affected by missing QCD corrections at higher orders for the jet functions in the associated factorization theorems. Their calculation is complicated by the jet clustering procedure. In this work, we propose a method to evaluate jet functions at higher orders in QCD. The calculation involves the phase space sector decomposition with suitable soft subtractions. As a concrete example, we present the quark-jet function using the anti-$k_T$ algorithm with E-scheme recombination at next-to-next-to-leading order.