Hadron Production and Propagation in Pion-Induced Reactions on Nuclei

TL;DR

This paper presents new experimental data on hadron production in pion-induced reactions on carbon and tungsten, compares it with transport models, and discusses the agreement and discrepancies to improve understanding of hadron dynamics.

Contribution

It provides the first comprehensive dataset of hadron production in pion-nucleus collisions at 1.7 GeV/c, extending existing data and testing transport models like GiBUU and SMASH.

Findings

Data significantly extend existing world data on pion-induced hadron production.

Comparison reveals areas of agreement and tension between models and experimental data.

Analysis of the $ ightarrow \Lambda + K_S^0 +X$ channel offers insights into strange hadron correlations.

Abstract

Hadron production ($\pi^\pm$, proton, $\Lambda$, $K_S^0$, $K^\pm$) in $\pi^- + \mathrm{C}$ and $\pi^- + \mathrm{W}$ collisions is investigated at an incident pion beam momentum of $1.7~\mathrm{GeV}/c$. This comprehensive set of data measured with HADES at SIS18/GSI significantly extends the existing world data on hadron production in pion induced reactions and provides a new reference for models that are commonly used for the interpretation of heavy-ion collisions. The measured inclusive differential production cross-sections are compared with state-of-the-art transport model (GiBUU, SMASH) calculations. The (semi-) exclusive channel $\pi^- + A \rightarrow \Lambda + K_S^0 +X$, in which the kinematics of the strange hadrons are correlated, is also investigated and compared to a model calculation. Agreement and remaining tensions between data and the current version of the considered transport models are discussed.