Asymmetries between the production of D+ and D- mesons from 500 GeV/c pi- nucleon interactions as a function of xF and pt**2

TL;DR

This paper investigates the asymmetries in D+ and D- meson production from 500 GeV/c pi- nucleon interactions, analyzing how these asymmetries depend on xF and pt^2, and compares experimental results with theoretical models.

Contribution

It provides detailed measurements of D+ and D- production asymmetries and demonstrates how adjusting PYTHIA parameters can align models with experimental data.

Findings

Measured asymmetries vary with xF and pt^2.

Default models do not match data, but PYTHIA can be tuned to do so.

Results highlight the importance of model parameter tuning for heavy-quark production.

Abstract

We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used.