Phase transitions at high and low densities for a rotating QCD matter from holography

TL;DR

The paper investigates how rotation and finite density reshape the QCD phase diagram within the exact soft-wall AdS/QCD framework by mapping confinement/deconfinement to Hawking-Page transitions between thermal AdS and rotating charged AdS$_5$ black holes. It derives the HP transition condition from the on-shell action difference, analyzes both high- and low-density regimes, and shows that relativistic rotation induces smooth crossovers at low density ($ l\gtrsim 0.16$) while high density remains governed by first-order transitions. A holographic critical point is estimated at $(\mu_{\text{CPB}},T_{\text{CP}})=(363.554\,\text{MeV},58.507\,\text{MeV})$, with a corresponding crossover region defined by $\bar{\mu}_{EF}^{\max}\approx0.414$, indicating a mixed phase of hadrons and QGP with different angular momenta at intermediate densities. The results highlight the significant impact of angular momentum on the QCD phase structure and offer a holographic, nonperturbative perspective on how rotation shapes confinement, deconfinement, and the possible location of a critical point.

Abstract

We applied the exact Andreev soft-wall holographic model to investigate phase transitions in rotating strongly interacting matter at high and low densities. Using the dual description of hadronic matter and quark-gluon plasma via thermal and charged black holes in five-dimensional AdS space with cylindrical symmetry, we find that for relativistic rotations exceeding 16\% of the speed of light, crossover transitions emerge in the low-density regime up to a critical baryon chemical potential $μ_{CPB}$. These smooth transitions, governed by the negative QCD $β$-function, describe a mixed phase of confined and deconfined matter with different angular momenta evolving into a pure plasma at very high temperatures. For $μ\geq μ_{CPB}$, first-order transitions dominate, following the critical-temperature curve of non-rotating matter. The critical point separating the low-density crossovers from high-density first-order transitions is numerically estimated as $(μ_{CPB}, T_{CP}) = (363.554, 58.507)\,\text{MeV}$.

Figures (11)

• Figure 1: Action density of non-rotating charged BH as a function of the horizon position in the exact Andreev's soft wall model at different quark chemical potentials.
• Figure 2: Phase diagram for a non-rotating QCD matter. Critical temperatures of deconfinement as a function of the quark chemical potential at $\omega l = 0$.
• Figure 3: Action density of a charged rotating BH as a function of the horizon position in Andreev's soft wall model, at a fixed plasma rotational velocity ($\omega l = 0.5$), and different quark chemical potentials.
• Figure 4: Action density of a rotating BH as a function of the horizon position in Andreev's soft wall model at zero density, with different rotational velocities.
• Figure 5: Phase transition at $\omega l = 0.4$. Action densities of a rotating charged BH as a function of horizon position in Andreev's soft-wall model, at different chemical potentials.