R-evolution: Improving perturbative QCD

Aug, 2009
4 pages
Published in:
  • Phys.Rev.D 82 (2010) 011501
e-Print:
Report number:
  • MIT-CTP-4062,
  • MPP-2009-156

Citations per year

2010201420182022202502468
Abstract: (arXiv)
Perturbative QCD results in the MSbar scheme can be dramatically improved by switching to a scheme that accounts for the dominant power law dependence on the factorization scale in the operator product expansion. We introduce the ``MSR scheme'' which achieves this in a Lorentz and gauge invariant way. The MSR scheme has a very simple relation to MSbar, and can be easily used to reanalyze MSbar results. Results in MSR depend on a cutoff parameter R, in addition to the mu of MSbar. R variations can be used to independently estimate i) the size of power corrections, and ii) higher order perturbative corrections (much like mu in MSbar). We give two examples at three-loop order, the ratio of mass splittings in the B*-B and D*-D systems, and the Ellis-Jaffe sum rule as a function of momentum transfer Q in deep inelastic scattering. Comparing to data, the perturbative MSR results work well even for Q ~ 1 GeV, and the size of power corrections is reduced compared to those in MSbar.
Note:
  • 4 pages, 3 figures, axis label for Fig.2 fixed
  • 12.38.Aw
  • 12.38.Bx
  • 11.15.Bt
  • 11.10.Gh
  • QCD
  • numerical analysis
  • supersymmetry
  • quantum chromodynamics
  • sum rule: Ellis-Jaffe
  • factorization