# Collective flow from AA, pA to pp collisions - Toward a unified paradigm

## TL;DR

This paper reviews recent progress in understanding collective phenomena across different collision systems, proposing a unified framework that explains observed collectivity in high-multiplicity hadronic events from AA, pA, to pp collisions.

## Contribution

It introduces a unified paradigm for describing collectivity in all hadronic collision systems, integrating experimental data with theoretical models.

## Key findings

- Evidence of collective behavior in small systems like pp and pA.
- A unified theoretical framework explains phenomena across all collision types.
- Discussion of future research directions in small-system collectivity.

## Abstract

I give an overview of the latest development in understanding collective phenomena in high-multiplicity hadronic final state from relativistic nucleus-nucleus, proton-nucleus and proton-proton collisions. Upon reviewing the experimental data and confronting them with theoretical models, a unified paradigm in describing the observed collectivity across all hadronic collision systems is emerging. Potential future paths toward addressing key open questions, especially on collectivity in small systems (pp, pA), are discussed.