Particle - antiparticle asymmetries in the production of baryons in 500 GeV/c pi^- Nucleon interactions

TL;DR

This paper reports the first high-statistics measurements of baryon-antibaryon asymmetries in 500 GeV/c pi^- Nucleon interactions, revealing leading particle effects across various hyperons and Lambda_c baryons.

Contribution

It provides new detailed measurements of baryon-antibaryon asymmetries as functions of x_F and p_T^2 in fixed target experiments, covering target and beam fragmentation regions.

Findings

Evidence of leading particle effects in asymmetries.

Asymmetries observed even at x_F=0.

First high-statistics measurements in these regions.

Abstract

We present the Fermilab E791 measurement of baryon - antibaryon asymmetries in the production of Lambda^0, Cascade, Omega and Lambda_c in 500 GeV/c pi^- Nucleon interactions. Asymmetries have been measured as a function of x_F and p_T**2 over the range -0.12 < x_F < 0.12 and p_T**2 < 4$ (GeV/c)**2 for hyperons and -0.1 < x_F < 0.3 and p_T**2 < 8 (GeV/c)**2 for the Lambda_c baryons. We observe clear evidence of leading particle effects and a basic asymmetry even at x_F=0. These are the first high statistics measurements of the asymmetry in both the target and beam fragmentation regions in a fixed target experiment.