Inverse Magnetic/Shear Catalysis

TL;DR

This paper investigates how both magnetic fields and angular momentum influence the phase transition temperatures in quark-gluon plasma, revealing that angular momentum can reinforce or diminish magnetic catalysis effects depending on chemical potential.

Contribution

It introduces a holographic approach to study the combined effects of magnetic fields and angular momentum on QGP phase transitions, a novel aspect not previously explored.

Findings

Angular momentum reinforces magnetic catalysis at low chemical potential.

At high chemical potential, angular momentum can decrease the magnetic effect.

The study provides a rough estimate of the relative impacts of magnetic fields and angular momentum.

Abstract

It is well known that very large magnetic fields are generated when the Quark-Gluon Plasma is formed during peripheral heavy-ion collisions. Lattice, holographic, and other studies strongly suggest that these fields may, for observationally relevant field values, induce "inverse magnetic catalysis", signalled by a lowering of the critical temperature for the chiral/deconfinement transition. The theoretical basis of this effect has recently attracted much attention; yet so far these investigations have not included another, equally dramatic consequence of the peripheral collision geometry: the QGP acquires a large angular momentum vector, parallel to the magnetic field. Here we use holographic techniques to argue that the angular momentum can also, independently, have an effect on transition temperatures, and we obtain a rough estimate of the relative effects of the presence of both a magnetic field and an angular momentum density. We find that the shearing angular momentum reinforces the effect of the magnetic field at low values of the baryonic chemical potential, but that it can actually decrease that effect at high chemical potentials.