Neutral kaon mixing from 2+1 flavor Domain Wall QCD

Antonio, D. J.; Boyle, P. A.; Blum, T.; Christ, N. H.; Cohen, S. D.; Dawson, C.; Izubuchi, T.; Kenway, R. D.; Jung, C.; Li, S.; Lin, M. F.; Mawhinney, R. D.; Noaki, J.; Ohta, S.; Pendleton, B. J.; Scholz, E. E.; Soni, A.; Tweedie, R. J.; Yamaguchi, A.

Neutral kaon mixing from 2+1 flavor Domain Wall QCD

Authors

Description

We present the first results for neutral kaon mixing using 2+1 flavors of domain wall fermions. A new approach is used to extrapolate to the physical up and down quark masses from our numerical studies with pion masses in the range 240 -- 420 MeV; only $SU(2)_L \times SU(2)_R$ chiral symmetry is assumed and the kaon is not assumed to be light. Our main result is $B_K^{\bar{\rm MS}}(2 \mathrm{GeV}) = 0.524(10)(28)$ where the first error is statistical and the second incorporates estimates for all systematic errors.
4 pages, 4 figures. RBC and UKQCD collaborations