Excited Hadron Channels in Hadronization

TL;DR

This paper enhances hadronization models by incorporating excited meson states and their decays, using quantum mechanics and PYTHIA simulations, revealing prolific production of certain excited states.

Contribution

It introduces a comprehensive method to include excited meson states in hadronization models and extends decay handling within PYTHIA, improving the realism of collision simulations.

Findings

States up to L=2 are produced profusely by quark recombination.

Inclusion of excited states affects the hadronization outcome.

The method aligns with observed resonance production patterns.

Abstract

The proper treatment of hadronic resonances plays an important role in many aspects of heavy ion collisions. This is expected to be the case also for hadronization, due to the large degeneracies of excited states, and the abundant production of hadrons from their decays. We first show how a comprehensive treatment of excited meson states can be incorporated into quark recombination, and in extension, into Hybrid Hadronization. We then discuss the quantum mechanics of forming excited states, utilizing the Wigner distribution functions of angular momentum eigenstates of isotropic 3-D harmonic oscillators. We further describe how resonance decays can be handled, based on a set of minimal assumptions, by creating an extension of hadron decays in PYTHIA 8. Finally, we present first results by simulating $e^+e^-$ collisions using PYTHIA and Hybrid Hadronization with excited mesons up to orbital angular momentum $L=4$ and radial quantum number 2. We find that states up to $L=2$ are produced profusely by quark recombination.