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Running coupling and the [Lambda] parameter from SU(3) lattice simulations

Journal Article · · Physical Review, D (Particles Fields); (United States)
;  [1]
  1. Physics Department, Bergische Universitaet, Gesamthochschule Wuppertal, Gauss-strasse 20, 5600 Wuppertal (Germany)
We present new results on the static [ital q[bar q]] potential from high-statistics simulations on 32[sup 4] and smaller lattices, using the standard Wilson action at [beta]=6.0, 6.4, and 6.8 on the Connection Machine CM-2. Within our statistical errors ([approx]1%) we do not observe any finite-size effects affecting the potential values, on varying the spatial lattice extent from 0.9 fm up to 3.3 fm. We are able to see and quantify the running of the coupling from the Coulomb behavior of the interquark force. From this we extract the ratio [radical][sigma] /[Lambda][sub [ital L]]. We demonstrate that scaling violations on the string tension can be considerably reduced by introducing effective coupling schemes, which allow for a safe extrapolation of [Lambda][sub [ital L]] to its continuum value. Both methods yield consistent values for [Lambda]: [Lambda][sub M[bar S]]=0.555[sub [minus]0.017][sup +0.019][times] [radical][sigma] =244[sub [minus]7][sup +8] MeV, where M[bar S] denotes the modified minimal subtraction scheme. At the highest-energy scale attainable to us we find [alpha](5 GeV)=0.150(3).
OSTI ID:
6943405
Journal Information:
Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 47:2; ISSN PRVDAQ; ISSN 0556-2821
Country of Publication:
United States
Language:
English