How the Blast-Wave Model Describes PID Hadron Spectra from 5 TeV p-Pb Collisions

TL;DR

This paper critically examines the application of the blast-wave model to 5 TeV p-Pb collision data, concluding that it does not validly describe the observed hadron spectra and questioning claims of collectivity in small systems.

Contribution

The paper provides a detailed analysis of the blast-wave model's limitations in describing p-Pb collision data, challenging its use as evidence for quark-gluon plasma formation in small systems.

Findings

Blast-wave model poorly fits the p-Pb spectra.

Model shape evolution does not match data trends.

Statistical measures show low fit quality.

Abstract

The blast-wave (BW) spectrum model has been applied extensively to nucleus-nucleus collision data with the intention to demonstrate formation of a quark-gluon plasma (QGP) in more-central A-A collisions. More recently the BW model has been applied to p-p, d-Au and p-Pb collisions. Such results are interpreted to indicate that ``collectivity'' (flows) and QGP appear in smaller systems. I consider variations of the BW model and supporting assumptions. In this talk I review BW analysis of identified-hadron spectra from 5 TeV p-Pb collisions and examine the shape evolution of model spectra with collision centrality. I evaluate data-model fit quality using conventional statistical measures. I conclude that the BW model is not a valid data model.