Convergence and gauge dependence properties of the resummed one loop quark quark scattering amplitude in perturbative QCD

Jul, 1997
21 pages
Published in:
  • Phys.Part.Nucl. 40 (2009) 353-367
e-Print:
Report number:
  • UGVA-DPNC-1997-7-171

Citations per year

19992005201120172023102
Abstract:
The one-loop QCD effective charge αseff\alpha_s^{eff} for quark-quark scattering is derived by diagrammatic resummation of the one-loop amplitude using an arbitary covariant gauge. Except for the particular choice of gauge parameter ξ=3,αseff\xi = -3, \alpha_s^{eff} is found to increase with increasing scale as lnQ\ln Q or ln2Q\ln^2 Q. For ξ=3,αseff\xi = -3, \alpha_s^{eff} decreases with increasing QQ and satisfies a renormalisation group equation. Experimental measurements of αs\alpha_s indicate, however, that in this case, αseff\alpha_s^{eff} is convergent only for scales \le 300 GeV.
Note:
  • 28 pages, 5 tables, 5 figures. v3 The one-loop amplitudes in Section 2 are recalculated using dimensional regularisation, and several errors in the on-shell calculation of Reference[1] are pointed out. v4 one figure removed one added. Three tables and new text in Section 5 added. Published version
  • 12.38.t
  • 12.38.Bx
  • 12.38.Cy
  • quark quark: scattering amplitude
  • quantum chromodynamics: perturbation theory
  • Feynman graph: higher-order
  • transformation: gauge
  • renormalization group
  • strong interaction: coupling constant
  • asymptotic freedom