2001/10/31 by A. Bode, H. Panagopoulos, Y. Proestos
Physics and Astronomy · #hep-lat
published as Nucl.Phys.Proc.Suppl. 106 (2002) 832-834 · 3 pages, contribution to Lattice2001(improvement). Longer write-ups of the two calculations can be found in hep-lat/0110211 and hep-lat/0108021
arxiv created 2001/10/31 · arxiv updated 2009/11/30
We calculate the 3-loop bare β-function of QCD, formulated on the lattice with the clover fermionic action. The dependence of our result on the number of colors N, the number of fermionic flavors Nf, and the clover parameter cSW, is shown explicitly. A direct outcome of our calculation is the two-loop relation between the bare coupling constant g0 and the one renormalized in the MS-bar scheme. Further, we can immediately derive the three-loop correction to the relation between the lattice Λ-parameter and g0, which turns out to be very pronounced. We also calculate the critical value of the hopping parameter, κc, in the clover action, to two loops in perturbation theory. This quantity is an additive renormalization; as such, it exhibits a linear divergence in the lattice spacing. We compare our results to non perturbative evaluations of κc coming from MC simulations.