Antenna subtraction at NNLO with identified hadrons

TL;DR

This paper extends the antenna subtraction method to NNLO QCD calculations involving identified hadrons in $e^+e^-$ collisions, introducing fragmentation antenna functions to handle collinear singularities.

Contribution

The work introduces fragmentation antenna functions for NNLO QCD calculations with identified hadrons, enabling precise subtraction of collinear singularities in fragmentation processes.

Findings

Fragmentation antenna functions are derived and integrated over phase space.

Cross-checks confirm the antenna functions match known NNLO coefficient functions.

The method improves the accuracy of theoretical predictions for hadron production.

Abstract

We extend the antenna subtraction method to include hadron fragmentation processes up to next-to-next-to-leading order (NNLO) in QCD in $e^+e^-$ collisions. To handle collinear singularities associated with the fragmentation process, we introduce fragmentation antenna functions in final-final kinematics with associated phase space mappings. These antenna functions are integrated over the relevant phase spaces, retaining their dependence on the momentum fraction of the fragmenting parton. The integrated antenna functions are cross-checked against the known NNLO coefficient functions for identified hadron production from $\gamma^*/Z^* \to q\bar{q}$ and $H \to gg$ processes.