Quantum Number Density Asymmetries Within QCD Jets Correlated With Lambda Polarization

TL;DR

This paper investigates how measuring Lambda particle polarization within QCD jets reveals nonperturbative quantum number asymmetries, offering insights into the hadronization process and internal jet structure.

Contribution

It introduces a method to study nonperturbative QCD effects through spin asymmetries of Lambda particles in jets, linking polarization measurements to internal quantum number distributions.

Findings

Lambda polarization correlates with local quantum number asymmetries.

Spin-directed asymmetries originate from nonperturbative mechanisms.

Insights into color rearrangement during hadronization are gained.

Abstract

The observation of jets in a variety of hard-scattering processes has allowed the quantitative study of perturbative quantum chromodynamics (PQCD) by comparing detailed theoretical predictions with a wide range of experimental data. This paper examines how some important, nonperturbative, facets of QCD involving the internal dynamical structure of jets can be studied by measuring the spin orientation of Lambda particles produced in these jets. The measurement of the transverse polarization for an individual Lambda within a QCD jet permits the definition of spin-directed asymmetries in local quantum number densities in rapidity space (such as charge, strangeness and baryon number densities) involving neighboring hadrons in the jet. These asymmetries can only be generated by soft, nonperturbative dynamical mechanisms and such measurements can provide insight not otherwise accessible into the color rearrangement that occurs during the hadronization stage of the fragmentation process.