Magnetized quark-gluon plasma at the LHC

Abstract: In QCD, the strengths of the large scale temperature dependent chromomagnetic, $B_3, B_8$, and usual magnetic, $H$, fields spontaneously generated in quark-gluon plasma after the deconfinement phase transition (DPT), are estimated. The consistent at high temperature effective potential accounting for the one-loop plus daisy diagrams is used. The heavy ion collisions at the LHC and temperatures T not much higher than the phase transition temperature $T_d$ are considered. The critical temperature for the magnetized plasma is found to be $T_d(H)$ ~ $110 - 120$ MeV. This is essentially lower compared to the zero field value $T_d(H=0)$~ $160-180$ MeV usually discussed in the literature. Due to contribution of quarks, the color magnetic fields act as the sources generating H. The strengths of the fields are $B_3(T), B_8(T) \sim 10^{18} - 10^{19}G, H(T) \sim 10^{16} - 10^{17}G$ for temperatures T ~ 160 - 220 MeV. At temperatures $T < 110 - 120$ MeV the effective potential minimum value being negative approaches to zero. This is signaling the absence of the background fields and color confinement.