出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present preliminary results from a 323 64 lattice calculation of the neutral kaon mixing
factor BK using 2+1 avours of DomainWall fermions, focussing on the chiral extrapolation and
non-perturbative renormalisation (NPR) of this quantity and comparing to our previous results
obtained from a 24364 lattice.
These simulations were performed using the Iwasaki gauge action at two different lattice spacings:
a1 = 1:729(28) GeV for the 24364 calculation and a1 = 2:42(4) 0:47
r0(fm) GeV for the 32364,
maintaining an approximately xed physical volume of (2:7fm)3.
In the discussion of the chiral extrapolation to the physical quark masses, we compare the ts
to an SU(2) partially-quenched chiral t form for which the kaon is coupled into the theory as
a heavy external particle. As the 323 64 results are preliminary at the time of writing we do
not present a result for the chiral extrapolation on this data set. Results for the 243 64 lattice
calculation have been published [1].
For the NPR we compare the stages of the calculation of the non-perturbative renormalisation constant
ZBK using the Rome-Southampton regularisation-invariant momentum scheme (RI/MOM),
where for the recent 32364 calculation we have used a lattice-volume source for the calculation
of the propagators, an approach which offers a substantial gain over the point source approach
used for the 243 64 calculation due to the volume averaging of the bilinear and four-quark
vertex locations.
