Asymmetries Between the Production of Ds- and Ds+ Mesons from 500 GeV/c pi- Nucleon Interactions as Functions of x_F and square of p_t

TL;DR

This study measures the production asymmetries of Ds- and Ds+ mesons in high-energy pion-nucleon interactions, finding results consistent with no net asymmetry and supporting the fragmentation process as the source of asymmetries.

Contribution

First measurement of Ds- and Ds+ production asymmetries as functions of x_F and p_t in 500 GeV/c pion-nucleon interactions, providing insights into charm meson production mechanisms.

Findings

No significant net asymmetry in Ds+- production.

Production asymmetries align with fragmentation process hypotheses.

Results consistent with previous D+- asymmetry observations.

Abstract

This paper presents measurements of the production of Ds- mesons relative to Ds+ mesons as functions of x_F and square of p_t for a sample of 2445 Ds decays to phi pi. The Ds mesons were produced in Fermilab experiment E791 with 500 GeV/c pi- mesons incident on one platinum and four carbon foil targets. The acceptance-corrected integrated asymmetry in the x_F range -0.1 to 0.5 for Ds+- mesons is 0.032 +- 0.022 +- 0.022, consistent with no net asymmetry. The results, as functions of x_F and square of p_t, are compared to predictions and to the large production asymmetry observed for D+- mesons in the same experiment. These comparisons support the hypothesis that production asymmetries come from the fragmentation process and not from the charm quark production itself.