# Mapping the Phases of Quantum Chromodynamics with Beam Energy Scan

## TL;DR

This paper reviews the current efforts and findings in searching for phase transitions, the critical point, and anomalous transport phenomena in Quantum Chromodynamics using the Beam Energy Scan program at RHIC.

## Contribution

It provides a comprehensive overview of experimental observables, results, and future directions in the quest to map QCD phases and critical phenomena.

## Key findings

- Experimental results suggest possible signals of the QCD critical point.
- Fluctuation and correlation measurements are key to identifying phase transitions.
- Further data and theoretical work are needed to confirm the existence of the critical point.

## Abstract

We review the present status of the search for a phase transition and critical point as well as anomalous transport phenomena in Quantum Chromodynamics (QCD), with an emphasis on the Beam Energy Scan program at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. We present the conceptual framework and discuss the observables deemed most sensitive to a phase transition, QCD critical point, and anomalous transport, focusing on fluctuation and correlation measurements. Selected experimental results for these observables together with those characterizing the global properties of the systems created in heavy ion collisions are presented. We then discuss what can be already learned from the currently available data about the QCD critical point and anomalous transport as well as what additional measurements and theoretical developments are needed in order to discover these phenomena.