We present a preliminary study of the neutral kaon mixing bag parameter BK using two flavors of dynamical Wilson fermions. We determine the matrix element of the relevant DeltaS=2 operator by using both the conventional approach and the so called ``non-subtraction method'', and find that the latter leads to results with smaller uncertainties. After having implemented non-perturbative renormalization, we study the dependence of BK on the see quark mass. At our relatively heavy values of quark masses (0.60<M_P/M_V<0.75) such a dependence is found to be negligible and the results, within the statistical accuracy, are consistent with a quenched determination. As a preliminary result for the renormalization group invariant parameter we quote BKRGI=1.02(25).
@article{arxiv.hep-lat/0510096,
title = {Kaon B-parameter with NF=2 dynamical Wilson fermions},
author = {F. Mescia and V. Gimenez and V. Lubicz and G. Martinelli and S. Simula and C. Tarantino},
journal= {arXiv preprint arXiv:hep-lat/0510096},
year = {2007}
}
Comments
Talk given at 23rd International Symposium on Lattice Field Field: Lattice 2005, Trinity College, Dublin, Ireland, 25-30 Jul 2005