出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present one- and two-loop results for the ghost propagator in Landau gauge calculated in
Numerical Stochastic Perturbation Theory (NSPT). The one-loop results are compared with available
standard Lattice Perturbation Theory in the infinite-volume limit. We discuss in detail how
to perform the different necessary limits in the NSPT approach and discuss a recipe to treat logarithmic
terms by introducing “finite-lattice logs”. We find agreement with the one-loop result
from standard Lattice Perturbation Theory and estimate, from the non-logarithmic part of the
ghost propagator in two-loop order, the unknown constant contribution to the ghost self-energy in
the RI’-MOM scheme in Landau gauge. That constant vanishes within our numerical accuracy.
