Strange quark chiral phase transition in hot 2+1-flavor magnetized quark matter

Using the Polyakov--Nambu--Jona-Lasinio model the strange quark chiral phase transition and the effect of its current mass on a hot magnetized three flavor quark matter at zero chemical potential is investigated. The impact of the 't Hooft mixing term on the restoration of the chiral symmetry on the light and strange sectors is studied and the critical temperature dependence on the magnetic field strength of the chiral strange transition is analyzed. It is shown that the s quark is much less sensitive to the magnetic field than the light quarks. Due to the 't Hooft term, it has a strong influence on the light quarks at all temperatures for small magnetic fields and for temperatures close to the transition temperature at zero magnetic field and above for strong magnetic fields. In particular, the large mass of the s quark makes the chiral transition of the light sector smoother and shifted to larger temperatures. A scalar coupling that weakens when the magnetic field increases will originate an inverse magnetic catalysis also in the s quark and smoothen the signature of the crossover on thermodynamical quantities such as the sound velocities or the specific heat.