Influence of chiral chemical potential, parallel electric, and magnetic fields on the critical temperature of QCD

We study the influence of external parallel electric and magnetic fields and a chiral chemical potential ${\ensuremath{\mu}}_{5}$ on the chiral phase transition of quantum chromodynamics. Our theoretical framework is a Nambu--Jona-Lasinio model with a contact interaction. Within this model we compute the critical temperature of chiral symmetry restoration ${T}_{c}$ as a function of the chiral chemical potential and field strengths. We find that the fields inhibit and ${\ensuremath{\mu}}_{5}$ enhances chiral symmetry breaking, in agreement with previous studies.