Speaker
Description
The sign problem interdicts lattice simulations at real non-zero values of the chemical potential: the computation of observables at imaginary values is a popular way out, but to make predictions for QCD at finite density one is left with the problem of the analytic continuation to the real axis, given a discrete set of measurements on the imaginary one. The Parma group has developed a method based on the Cauchy integral formula, which is first discretised à la Gauss Legendre and then solved as an inverse problem. We present the state of the art, focusing on the statistical and systematic effects affecting the final results, which are probed both for (analytic) test functions, and for lattice QCD data (obtained by the Bielefeld-Parma collaboration). We will show the analytic continuation of the $N_f=2+1$ net baryon-number density at physical quark mass. Higher-order cumulants evaluated at $\mu=0$ will be presented and compared to the ones already published in the literature. A new estimate for the 10th order cumulant will also be provided.