Color reconnection effects on resonance production

TL;DR

This paper investigates how color reconnection and multi-parton interactions influence resonance production in proton-proton collisions, revealing mechanisms that suppress meson resonances and explaining experimental observations.

Contribution

It demonstrates that color reconnection reduces meson resonance yields by creating shorter, less energetic strings, offering a novel explanation for resonance suppression in high-multiplicity pp collisions.

Findings

Color reconnection suppresses meson resonance production.

Shorter, less energetic strings lead to reduced resonance yields.

String junctions may also contribute to resonance suppression.

Abstract

We present studies that show how multi-parton interaction and color reconnection affect the hadro-chemistry in proton-proton (pp) collisions with special focus on the production of resonances using the PYTHIA8 event generator. We find that color reconnection suppresses the relative production of meson resonances such as $\rho_{0}$ and K*, providing an alternative explanation for the K*/K decrease observed in proton-proton collisions as a function of multiplicity by the ALICE collaboration. Detailed studies of the underlying mechanism causing meson resonance suppression indicate that color reconnection leads to shorter, less energetic strings whose fragmentation is less likely to produce more massive hadrons for a given quark content, therefore reducing ratios such as K*/K and $\rho_0/\pi$ in high-multiplicity pp collisions. In addition, we have also studied the effects of allowing string junctions to form and found that these may also contribute to resonance suppression.