Susceptibilities from a black hole engineered EoS with a critical point

TL;DR

This paper uses a holographic black hole model to study higher-order susceptibilities of net-baryon charge, aiming to identify signatures of the QCD critical point by comparing with experimental data from RHIC's beam energy scan.

Contribution

It introduces a black hole engineered holographic model that captures critical point behavior and matches lattice susceptibilities, providing a new tool to analyze experimental data for the QCD critical point.

Findings

The holographic model reproduces lattice susceptibilities at zero chemical potential.

Analysis of STAR data suggests potential signatures of the critical point at low energies.

Higher-order fluctuations show deviations consistent with critical phenomena.

Abstract

Currently at the Beam Energy Scan at RHIC experimental efforts are being made to find the QCD critical point. On the theoretical side, the behavior of higher-order susceptibilities of the net-baryon charge from Lattice QCD at $\mu_{_B}\!=\!0$ may allow us to estimate the position of the critical point in the QCD phase diagram. However, even if the series expansion continues to higher-orders, there is always the possibility to miss the critical point behavior due to truncation errors. An alternative approach is to use a black hole engineered holographic model, which displays a critical point at large densities and matches lattice susceptibilities at $\mu_{_B}\!=\!0$. Using the thermodynamic data from this black hole model, we obtain the freeze-out points extracted from the net-protons distribution measured at STAR and explore higher order fluctuations at the lowest energies at the beam energy scan to investigate signatures of the critical point.