Topological susceptibility and chiral condensate with $N_f=2+1+1$ dynamical flavors of maximally twisted mass fermions

Abstract

We study the 'spectral projector' method for the computation of the chiral condensate and the topological susceptibility, using $N_f=2+1+1$ dynamical flavors of maximally twisted mass Wilson fermions. In particular, we perform a study of the quark mass dependence of the chiral condensate $\Sigma$ and topological susceptibility ${\chi }_{top}$ in the range $270MeV<m_{\pi }<500MeV$ and compare our data with analytical predictions. In addition, we compute ${\chi }_{top}$ in the quenched approximation where we match the lattice spacing to the $N_f=2+1+1$ dynamical simulations. Using the Kaon, $\eta$ and ${\eta }^{\prime }$ meson masses computed on the $N_f=2+1+1$ ensembles, we then perform a preliminary test of the Witten-Veneziano relation.

Comments: 7 pages, 6 figures. Talk given at the XXIX International Symposium on Lattice Field Theory - Lattice 2011, Lake Tahoe, California, USA