出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present the corrections to the fermion propagator, to second order in the lattice spacing
a, in 1-loop perturbation theory. The fermions are described by the clover action and for the
gluons we use a 3-parameter family of Symanzik improved actions. Our calculation has been
carried out in a general covariant gauge. The results are provided as a polynomial of the clover
parameter cSW, and are tabulated for 10 popular sets of the Symanzik coefficients (Plaquette,
Tree-level Symanzik, Iwasaki, TILW and DBW2 action). • We also study the O(a2) corrections
to matrix elements of fermion bilinear operators that have the form YGY, where G denotes all
possible distinct products of Dirac matrices. These correction terms are essential ingredients for
improving, to O(a2), the matrix elements of the fermion operators. • Our results are applicable
also to the case of twisted mass fermions.
A longer write-up of this work, including non-perturbative results, is in preparation together with
V. Giménez, V. Lubicz and D. Palao [1].
