Quantum Computing Hadron Fragmentation Functions in Light-Front Chromodynamics

TL;DR

This paper introduces a quantum simulation approach to compute hadron fragmentation functions in light-front QCD, demonstrating a proof-of-concept for calculating charm quark fragmentation into charmonium, which was previously intractable.

Contribution

It presents the first method to calculate fragmentation functions using quantum computing techniques within light-front QCD, bridging a gap in ab-initio approaches.

Findings

Successfully computed charm-to-J/psi fragmentation in a simplified model.

Validated quantum simulation results against known perturbative calculations.

Showed feasibility of quantum algorithms for complex QCD calculations.

Abstract

We deploy Quantum Chromodynamics (QCD) in Light-front Quantization (and Gauge), discretized and truncated in both Fock -- and momentum -- spaces with a particle-register encoding suited for quantum simulation; we show for the first time how to calculate fragmentation functions, a problem heretofore untractable in general from \emph{ab-initio} approaches. We provide a classical-simulator based proof-of-concept by computing the charm-to-charmonium fragmentation, $c\to J/\psi$, in a simplified setup, an interesting case where we can (reasonably) compare with the known 1993 perturbative evaluation within Nonrelativistic QCD.