English

Analytic Model for the QCD Running Coupling with Universal $\bar{\alpha}_s(0)$ Value

High Energy Physics - Phenomenology 2009-10-30 v1

Abstract

We discuss the new model expression αˉan(Q2)\bar{\alpha}_{an}(Q^2) recently obtained for the QCD running coupling with a regular ghost-free behavior in the "low Q2Q^2" region. Being deduced from the standard "asymptotic-freedom" expression by imposing the Q2Q^2-analyticity -- without any adjustable parameters -- it obeys nice features: (i) The universal limiting value αˉan(0)=4π/β01.4\bar{\alpha}_{an}(0)=4\pi /\beta_0 \simeq 1.4 expressed only via group symmetry factors and independent of experimental estimates on the running coupling αˉs(Q2)\bar{\alpha}_s(Q^2) (of QCD scale parameter Λ\Lambda). This value turns out to be stable with respect to higher order corrections; (ii) Stability of IR behavior with respect to higher-loop effects; (iii) Coherence between the experimental αˉan(Mτ2)\bar{\alpha}_{an}(M_{\tau}^2) value and integral information on IR αˉs(Q2)\bar{\alpha}_s(Q^2) behavior as extracted from jet physics data.

Keywords

Cite

@article{arxiv.hep-ph/9704333,
  title  = {Analytic Model for the QCD Running Coupling with Universal $\bar{\alpha}_s(0)$ Value},
  author = {D. V. Shirkov and I. L. Solovtsov},
  journal= {arXiv preprint arXiv:hep-ph/9704333},
  year   = {2009}
}

Comments

8 pages, LaTex with psfig.sty, 2 PostScript figures

R2 v1 2026-07-22T14:36:47.562Z