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Kaon B-parameter with NF=2 dynamical Wilson fermions

F. Mescia·V. Gimenez·V. Lubicz·G. Martinelli·S. Simula·C. Tarantino
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Abstract

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).

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F. Mescia, V. Gimenez, V. Lubicz, G. Martinelli, S. Simula, C. Tarantino. 2005-10-23. Kaon B-parameter with NF=2 dynamical Wilson fermions. https://arxiv.org/abs/hep-lat/0510096

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