QCD Crossover at Finite Chemical Potential from Lattice Simulations

We provide the most accurate results for the QCD transition line so far. We optimize the definition of the crossover temperature T_{c}, allowing for its very precise determination, and extrapolate from imaginary chemical potential up to real μ_{B}≈300  MeV. The definition of T_{c} adopted in this work is based on the observation that the chiral susceptibility as a function of the condensate is an almost universal curve at zero and imaginary μ_{B}. We obtain the parameters κ_{2}=0.0153(18) and κ_{4}=0.00032(67) as a continuum extrapolation based on N_{t}=10, 12, 16 lattices with physical quark masses. We also extrapolate the peak value of the chiral susceptibility and the width of the chiral transition along the crossover line. In fact, both of these are consistent with a constant function of μ_{B}. We see no sign of criticality in the explored range.