Initial value problem for magnetic field in heavy ion collisions

TL;DR

This paper solves the initial value problem for magnetic fields in heavy-ion collisions, showing that the initial magnetic field dominates and significantly influences quark-gluon plasma evolution at high energies.

Contribution

It provides a novel solution to the initial magnetic field evolution in plasma, highlighting the dominance of the initial field over induced fields in heavy-ion collisions.

Findings

Initial magnetic field often dominates over induced fields.

Magnetic field strength grows approximately with collision energy.

Magnetic field significantly affects quark-gluon plasma dynamics.

Abstract

When quark-gluon plasma emerges in the wake of a heavy-ion collision, magnetic field created by the valence charges has already permitted the entire interaction region. Evolution of this "initial" field in plasma is governed by Maxwell equations in electrically conducting medium. As the plasma expands external valence charges induce magnetic field that also contributes to the total magnetic field in plasma. We solve the initial value problem describing these processes and argue that the initial magnetic field often dominates over the one induced by the valence charges. In particular, it grows approximately proportional to the collision energy, unlike the induced component, which is energy-independent. As a result, magnetic field has a significant phenomenological influence on quark-gluon plasma at the LHC energies over its entire lifetime.