Speaker
Description
We calculate Fourier coefficients of the net-baryon number as a function
of a purely imaginary chemical potential. The asymptotic behavior of
these coefficients is governed by the singularity structure of the QCD
partition function and thus encodes information on phase
transitions. Although it is not easy to obtain a high number of Fourier
coefficients from lattice QCD data directly, models for these
coefficients have been constructed in the past. We investigate to what
extent our data is consistent with those models and estimate the
position of the nearest singularities in the complex chemical potential
plane. Our lattice data has been obtained from simulations with
(2+1)-flavors of highly improved staggered quarks (HISQ) at imaginary
chemical potential on $N_\tau=4$, $6$ and $8$ lattices at physical quark
masses. For the calculation of the Fourier coefficients we apply
asymptotic numerical quadrature designed for highly oscillatory integrals.
