Non-perturbative renormalization of quark bilinear operators with N f = 2 (tmQCD) Wilson fermions and the tree-level improved gauge action
Date
2010Author
Constantinou, Martha G.Dimopoulos, Petros
Frezzotti, R.
Herdoiza, G.
Jansen, K.
Lubicz, V.
Panagopoulos, Haralambos G.
Rossi, G. C.
Simula, S.
Stylianou, Fotos S.
Vladikas, A.
ISSN
1126-6708Source
Journal of High Energy PhysicsVolume
2010Issue
8Google Scholar check
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We present results for the renormalization constants of bilinear quark operators obtained by using the tree-level Symanzik improved gauge action and the N f = 2 twisted mass fermion action at maximal twist, which guarantees automatic O(a)-improvement. Our results are also relevant for the corresponding standard (un-twisted) Wilson fermionic action since the two actions only differ, in the massless limit, by a chiral rotation of the quark fields. The scale-independent renormalization constants Z V, Z A and the ratio Z P /Z S have been computed using the RI-MOMapproach, as well as other alternative methods. For Z A and Z P /Z S, the latter are based on both standard twisted mass and Osterwalder-Seiler fermions, while for Z V a Ward Identity has been used. The quark field renormalization constant Z q and the scale dependent renormalization constants Z S, Z P and Z T are determined in the RI-MOM scheme. Leading discretization effects of O(g 2a 2), evaluated in one-loop perturbation theory, are explicitly subtracted from the RI-MOM estimates. © 2010 SISSA, Trieste, Italy.