Determining the strange quark mass for 2-flavour QCD
  Using the O(a) Symanzik improved action an estimate is given for the strange quark mass for unquenched (n_f=2) QCD. The determination is via the axial Ward identity (AWI) and includes a non-perturbative evaluation of the renormalisation constant. Numerical results have been obtained at several lattice spacings, enabling the continuum limit to be taken. Our results indicate a value for the strange quark mass (in the MS-bar scheme at a scale of 2 GeV) in the range 100 - 130 MeV. A comparison is also made with other recent lattice determinations of the strange quark mass using dynamical sea quarks. 
M. G\"ockeler, R. Horsley, A. C. Irving, D. Pleiter, P. E. L. Rakow,   G. Schierholz, H. St\"uben, J. M. Zanotti