FI: FINITE-DENSITY QCD TRANSITION IN MAGNETIC FIELD BACKGROUND - DOTT. ANDREY KOTOV
SEZIONE DI FIRENZE In this talk we discuss the influence of magnetic-field background on
chiral and deconfinement crossovers in finite-temperature QCD at low
baryonic density. To address this problem we perform numerical
simulation of lattice QCD with 2+1 physical quark masses at nonzero
temperature, magnetic field and imaginary chemical potential. Results
for real values of chemical potential are obtained by means of
analytical continuation. In the absence of thermodynamic singularity,
we identify the phase transitions with inflection points of the
approximate order parameters: normalized light-quark condensate and
renormalized Polyakov loop, respectively.
We show that the quadratic curvature of the chiral transition
temperature in the temperature-chemical potential plane depends rather
weakly on the strength of the background magnetic field. At weak
magnetic fields, the thermal width of the chiral crossover gets
narrower as the density of the baryon matter increases, possibly
indicating a proximity to a real thermodynamic phase transition.
Remarkably, the curvature of the chiral thermal width flips its sign
at $eB_{ ext{fl}} simeq 0.6,mathrm{GeV}^2$, so that above the
flipping point $B > B_{ ext{fl}}$, the chiral width gets wider as the
baryon density increases. Approximately at the same strength of
magnetic field, the chiral and deconfining crossovers merge together
at $T pprox 140,mathrm{MeV}$. The phase diagram in the parameter
space temperature-chemical potential-magnetic field is outlined.
The talk is based on the paper arXiv:1909.09547. (dott. Andrey Kotov)
DATA: 21-11-2019
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