The crossover line in the (T, mu)-phase diagram of QCD

An efficient way to study the QCD phase diagram at small finite density is to extrapolate thermodynamical observables from imaginary chemical potential. The phase diagram features a crossover line starting from the transition temperature already determined at zero chemical potential. In this work we focus on the Taylor expansion of this line up to mu(4) contributions. We present the continuum extrapolation of the crossover temperature based on different observables at several lattice spacings.