Abstract
We calculate the critical value of the hopping parameter, in improved lattice QCD, to two loops in perturbation theory. We employ the Sheikholeslami-Wohlert (clover) improved action for Wilson fermions. 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. The dependence of our results on the number of colors N, the number of fermionic flavors, and the clover parameter is shown explicitly. We compare our results with nonperturbative evaluations of coming from Monte Carlo simulations.
- Received 16 August 2001
DOI:https://doi.org/10.1103/PhysRevD.65.014511
©2001 American Physical Society