We analyze general convergence properties of the Taylor expansion of observables to finite chemical potential in the framework of an effective 2+1 flavor Polyakov-quark-meson model. To compute the required higher order coefficients a novel technique based on algorithmic differentiation has been developed. Results for thermodynamic observables as well as the phase structure obtained through the series expansion up to 24th order are compared to the full model solution at finite chemical potential. The available higher order coefficients also allow for resummations, e.g. Pade series, which improve the convergence behavior. In view of our results we discuss the prospects for locating the QCD phase boundary and a possible critical endpoint with the Taylor expansion method.
Proceedings of the XXIX International Symposium on Lattice Field Theory (Lattice 2011). July 10-16
- Pub Date:
- High Energy Physics - Lattice;
- High Energy Physics - Phenomenology
- 7 pages, 4 figures. Contribution to the XXIX International Symposium on Lattice Field Theory, July 10 - 16 2011, Squaw Valley, Lake Tahoe, California