Kaon B-parameter from quenched domain-wall QCD

We report on a calculation of B-K with domain wall fermion action in quench ed QCD. Simulations are made with a renormalization group improved gauge ac tion at beta = 2.6 and 2.9 corresponding to a(-1) approximate to 2GeV and 3 GeV. Effects due to finite fifth dimensional size N-5 and finite spatial si ze N-sigma are examined in detail. Matching to the continuum operator is ma de perturbatively at one loop order. We obtain B-K (mu = 2GeV) = 0.5746(61) , where the error is statistical only, as an estimate of the continuum valu e in the (MS) over bar scheme with naive dimensional regularization. This v alue is smaller but consistent with B-K (mu = 2GeV) = 0.628(42) obtained by the JLQCD Collaboration using the Kogut-Susskind quark action. Results for strange quark mass are also reported.