Mass-dependent transport of hadron species from soft to hard (nonjet to jet) spectrum components within small collision systems at the large hadron collider

TL;DR

This paper demonstrates that in small collision systems at the LHC, hadron species are transported from soft to hard spectrum components in a mass-dependent manner, consistent with a two-component model and conservation principles.

Contribution

It reveals that hadron species transport from soft to hard components depends on mass and increases with jet activity, extending the two-component model analysis.

Findings

Transport of hadron species increases with jet production.

Transport extent is proportional to hadron mass.

Total particle number per species is conserved.

Abstract

In previous analyses a two-component (soft+hard) model (TCM) was developed for identified-hadron (PID) spectra from 5 TeV $p$-Pb and 13 TeV $p$-$p$ collisions. Spectrum data are generally described within their statistical uncertainties. Within the model are coefficients $z_{si}(n_s)$ and $z_{hi}(n_s)$ that denote the fractions of hadron species $i$ within total soft $\bar \rho_s$ and hard $\bar \rho_h$ charge densities and that vary significantly with event index $n_s = \Delta \eta \bar \rho_s$. This letter reports that variation of those coefficients with $n_s$ implies transport of hadron species from soft component to hard component, increasingly with increased jet production, while conserving the total particle number for each species that is predicted by a statistical model. The extent of transport is simply proportional to hadron mass.