Chiral condensate from the twisted mass Dirac operator spectrum
K. Cichy1,2 , E. Garcia-Ramos 1,3 , K. Jansen1,4
2 Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614, Poznan, Poland
3 Humboldt Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany
1 NIC, DESY Zeuthen, Platanenallee 6, 15738 Zeuthen, Germany
4 Department of Physics, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
Journal of High Energy Physics, 1310, 175 (2013)
We present the results of our computation of the dimensionless chiral condensate r 0Σ1/3 with N f = 2 and N f = 2 + 1 + 1 flavours of maximally twisted mass fermions. The condensate is determined from the Dirac operator spectrum, applying the spectral projector method proposed by Giusti and Lüscher. We use 3 lattice spacings and several quark masses at each lattice spacing to perform the chiral and continuum extrapolations. We study the effect of the dynamical strange and charm quarks by comparing our results for N f = 2 and N f = 2 + 1 + 1 dynamical flavours.