Two-loop additive mass renormalization with clover fermions and Symanzik improved gluons
Ημερομηνία
2008ISSN
1550-7998Source
Physical Review D - Particles, Fields, Gravitation and CosmologyVolume
77Issue
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Metadata
Εμφάνιση πλήρους εγγραφήςΕπιτομή
We calculate the critical value of the hopping parameter, κc, in lattice QCD, up to two loops in perturbation theory. We employ the Sheikholeslami-Wohlert (clover) improved action for fermions and the Symanzik improved gluon action with 4- and 6-link loops. The quantity which we study is a typical case of a vacuum expectation value resulting in an additive renormalization as such, it is characterized by a power (linear) divergence in the lattice spacing, and its calculation lies at the limits of applicability of perturbation theory. Our results are polynomial in cSW (clover parameter) and cover a wide range of values for the Symanzik coefficients ci. The dependence on the number of colors N and the number of fermion flavors Nf is shown explicitly. In order to compare our results to nonperturbative evaluations of κc coming from Monte Carlo simulations, we employ an improved perturbation theory method for improved actions. © 2008 The American Physical Society.