## Landau gauge ghost propagator and running coupling in SU(2) lattice gauge theory    [PDF]

V. G. Bornyakov, E. -M. Ilgenfritz, C. Litwinski, V. K. Mitrjushkin, M. Muller-Preussker
We study finite (physical) volume and scaling violation effects of Landau gauge ghost propagator as well as of the running coupling alpha_s(p) in the SU(2) lattice gauge theory. We consider lattices with physical sizes between 3 and 7 fm and values of spacing a between 0.2 and 0.07 fm. To fix the gauge we apply an efficient gauge fixing method aimed at finding extrema as close as possible to the global maximum of the gauge functional. We show that finite volume effects turn out to be rather small for momenta |p| > 0.6 GeV. The relative scaling violations for alpha_s(p) do not exceed 10% within the bare coupling range beta=4/g_0^2 \in [2.30, 2.55] for the same momentum region and decreases quickly with increasing |p|. Our results testify in favor of the decoupling behavior.
View original: http://arxiv.org/abs/1302.5943