Perturbative determination of O(am) improvement on the QCD running coupling

2025/03/01 by Costa, Marios, Gavriel, Demetrianos, Panagopoulos, Haralambos +1
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat)

paper · doi:10.48550/arxiv.2503.00463

Abstract

We present the perturbative results of the discretization errors proportional to the quark mass (O(a m)) on the QCD running coupling within lattice perturbation theory. Our analysis involves calculating the 2-loop renormalization factor Z_g using improved lattice actions for the SU(N_c) gauge group and N_f multiplets of fermions with a finite quark mass. We employ the background field method to compute Z_g, by calculating quantum corrections on both the background and quantum gluon propagator, respecting the O(a) improvement. This allows us to evaluate the perturbative O(a m) lattice errors which affect the determination of the running coupling. Eliminating these O(a m) effects is crucial for the nonperturbative studies of precision determinations of the strong coupling constant using lattice field theory.

Related

• Non-perturbative QCD: renormalization, O(a)-improvement and matching to Heavy Quark Effective Theory
• Non-perturbative computation of the strong coupling constant on the\n lattice
• Hadronic contribution to the running of the electromagnetic coupling constant from lattice QCD: challenges at short distances
• Investigation of the Perturbative Expansion of Moments of Heavy Quark\n Correlators for N_f=0
• O(a) improved quark mass renormalization for a non-perturbative matching of HQET to three-flavor QCD