出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We briey report our calculation of the 2-loop coefficient of the coupling constant renormalization
function Zg in lattice perturbation theory. The quantity under study is defined through g0 = Zg g,
where g0 (g) is the bare (renormalized) coupling constant. The 2-loop expression for Zg can be
directly related to the 3-loop bare b -function bL(g0).
Our calculation is performed using overlap fermions and Wilson gluons, and the background
field technique has been chosen for convenience. Our results depend explicitly on the number
of fermion avors (Nf ) and colors (N). Since the dependence of Zg on the overlap parameter r
cannot be extracted analytically, we tabulate our results for different values of r in the allowed
range (0 < r < 2), focusing on values which are being used most frequently in simulations.
Plots of the 1- and 2-loop results for Zg versus r exhibit a non-trivial dependence on the overlap
parameter.
