# Analysing radial flow features in p-Pb and p-p collisions at several TeV by studying identified particle production in EPOS3

## TL;DR

This paper uses EPOS3, a hydrodynamical event generator, to analyze identified particle spectra in p-Pb and p-p collisions at several TeV, revealing flow-like effects similar to those in Pb-Pb collisions.

## Contribution

It demonstrates that EPOS3 can quantitatively reproduce flow-like features in small collision systems, highlighting the role of hydrodynamics and flux tube initial conditions.

## Key findings

- p-Pb and p-p spectra show flow effects similar to Pb-Pb.
- Enhanced intermediate $p_{t}$ particle production increases with hadron mass.
- EPOS3 accurately models identified particle spectra in small systems.

## Abstract

Experimental transverse momentum spectra of identified particles in p-Pb collisions at 5.02 TeV show many similarities to the corresponding Pb-Pb results, the latter ones usually being interpreted in term of hydrodynamic flow. We analyse these data using EPOS3, an event generator based on a 3D+1 viscous hydrodynamical evolution starting from flux tube initial conditions, which are generated in the Gribov-Regge multiple scattering framework. An individual scattering is referred to as Pomeron, identified with a parton ladder, eventually showing up as flux tubes (or strings). Each parton ladder is composed of a pQCD hard process, plus initial and final state linear parton emission. Nonlinear effects are considered by using saturation scales $Q_{s}$, depending on the energy and the number of participants connected to the Pomeron in question. We compute transverse momentum ($p_{t}$) spectra of pions, kaons, protons, lambdas, and $\Xi$ baryons in p-Pb and p-p scattering, compared to experimental data and many other models. In this way we show in a quantitative fashion that p-Pb data (and even p-p ones) show the typical ``flow effect'' of enhanced particle production at intermediate $p_{t}$ values, more and more visible with increasing hadron mass.