Spin Correlations of Lambda anti-Lambda Pairs as a Probe of Quark-Antiquark Pair Production

TL;DR

This paper explores how spin correlations of Lambda and anti-Lambda pairs can reveal the production mechanisms of strange quark-antiquark pairs during hadronization in high-energy collisions.

Contribution

It introduces a method to analyze Lambda anti-Lambda spin correlations to differentiate between various s anti-s pair production states and mechanisms.

Findings

Templates for angular correlations in different spin states

Potential to distinguish production mechanisms in experiments

Framework applicable to pp and heavy-ion collisions

Abstract

The polarizations of Lambda and anti-Lambda are thought to retain memories of the spins of their parent s quarks and antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of Lambda and anti-Lambda produced at low relative momenta may therefore be used to probe the spin states of s anti-s pairs produced during hadronization. We consider the possibilities that they are produced in a 3P_0 state, as might result from fluctuations in the magnitude of <anti-s s>, a 1S_0 state, as might result from chiral fluctuations, or a 3S_1 or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti-p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti-s production mechanisms in pp and heavy-ion collisions.