Identified Charged Particles in Quark and Gluon Jets

TL;DR

This study measures the distributions of identified particles in quark and gluon jets from Z decays, revealing differences in particle spectra and baryon production, with implications for understanding hadronization.

Contribution

It provides an improved measurement of identified particle distributions in quark and gluon jets, highlighting differences in spectra and baryon production mechanisms.

Findings

Gluon jets have softer particle spectra than quark jets.

Higher multiplicity of particles observed in gluon jets.

Proton production is significantly enhanced in gluon jets.

Abstract

A sample of 2.2 million hadronic Z decays, selected from the data recorded by the Delphi detector at LEP during 1994-1995 was used for an improved measurement of inclusive distributions of pi+, K+ and p and their antiparticles in gluon and quark jets. The production spectra of the individual identified particles were found to be softer in gluon jets compared to quark jets, with a higher multiplicity in gluon jets as observed for inclusive charged particles. A significant proton enhancement in gluon jets is observed indicating that baryon production proceeds directly from colour objects. The maxima, xi^*, of the xi-distributions for kaons in gluon and quark jets are observed to be different.