# Critical point in the phase diagram of primordial quark-gluon matter from black hole physics

## TL;DR

This paper uses holographic black hole models to predict the existence and location of a critical point in the phase diagram of dense quark-gluon matter, which could be observed in heavy ion collisions.

## Contribution

It introduces a holographic approach to study baryon charge fluctuations and predicts the critical point in the QCD phase diagram beyond lattice QCD capabilities.

## Key findings

- Reproduces lattice QCD results for baryon fluctuation moments
- Predicts higher order baryon susceptibilities
- Locates the critical point within experimental reach

## Abstract

Strongly interacting matter undergoes a crossover phase transition at high temperatures $T\sim 10^{12}$ K and zero net-baryon density. A fundamental question in the theory of strong interactions, Quantum Chromodynamics (QCD), is whether a hot and dense system of quarks and gluons displays critical phenomena when doped with more quarks than antiquarks, where net-baryon number fluctuations diverge. Recent lattice QCD work indicates that such a critical point can only occur in the baryon dense regime of the theory, which defies a description from first principles calculations. Here we use the holographic gauge/gravity correspondence to map the fluctuations of baryon charge in the dense quark-gluon liquid onto a numerically tractable gravitational problem involving the charge fluctuations of holographic black holes. This approach quantitatively reproduces ab initio results for the lowest order moments of the baryon fluctuations and makes predictions for the higher order baryon susceptibilities and also for the location of the critical point, which is found to be within the reach of heavy ion collision experiments.