Quark mass dependence of pseudo-scalar masses and coupling constants

The dependence of pseudo-scalar masses and decay constants on the sea and valence quark masses is investigated in the pseudo-Goldstone boson sector of QCD with two light quark flavours. The sea quark masses are at present in the range 1/3m(s) < m(ud) < 2/3m(s) whereas the valence quark masses satisfy 1/2m(sea) less than or equal to m(val) less than or equal to 2m(sea). The values of the Gasser-Leutwyler low energy constants L-4, L-5, L-6 and L-8 are estimated. The computation is done with the Wilson-quark lattice action at gauge coupling beta = 5.1 on 16(4) lattices. O(a) effects are taken into account by applying chiral perturbation theory for the Wilson lattice action as proposed by Rupak and Shoresh.