A precise determination of B_K in quenched QCD
Citation:
Petros Dimopoulos, Jochen Heitger, Filippo Palombi, Carlos Pena, Stefan Sint, Anastassios Vladikas, A precise determination of B_K in quenched QCD, Nuclear Physics B, 749, 2006, 69, 108Download Item:
Abstract:
The
B
K
parameter is computed in quenched lattice QCD with Wilson twisted mass fermions. Two
variants of tmQCD are used; in both of them the relevant
S
=
2 four-fermion operator is renormalised
multiplicatively. The renormalisation adopted is non-perturbative, with a Schrödinger functional renormal-
isation condition. Renormalisation group running is also non-perturbative, up to very high energy scales.
In one of the two tmQCD frameworks the computations have been performed at the physical
K
-meson
mass, thus eliminating the need of mass extrapolations. Simulations have been performed at several lattice
spacings and the continuum limit was reached by combining results from both tmQCD regularisations. Fi-
nite volume effects have been partially checked and turned out to be small. Exploratory studies have also
been performed with non-degenerate valence flavours. The final result for the RGI bag parameter, with all
sources of uncertainty (except quenching) under control, is
ˆ
B
K
=
0
.
789
±
0
.
046.
Author's Homepage:
http://people.tcd.ie/sints
Author: SINT, STEFAN
Type of material:
Journal ArticleSeries/Report no:
Nuclear Physics B749
Availability:
Full text availableKeywords:
quenched lattice QCDDOI:
http://dx.doi.org/10.1016/j.nuclphysb.2006.04.033Metadata
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