Jul 2014
ΛMS(nf=2) from a momentum space analysis of the quark-antiquark static potential
published in: JHEP 1409, 114 (2014)
arXiv: 1407.7503 [hep-ph]
download: 1407.7503v1.ps.gz, 1407.7503v1.pdf (paper, 26 pages)
abstract:
We determine ΛMS(nf=2) by fitting perturbative expressions for the quark-antiquark static potential to lattice results for QCD with nf = 2 dynamical quark flavors. To this end we use the perturbative static potential at the presently best known accuracy, i.e. up to O(αs4), in momentum space. The lattice potential is computed on a fine lattice with a = 0.042 fm in position space. To allow for a comparison and matching of both results, the lattice potential is transformed into momentum space by means of a discrete Fourier transform. The value of ΛMS(nf=2) is extracted in momentum space. All sources of statistical and systematic errors are discussed. The uncertainty in the value of ΛMS(nf=2) is found to be smaller than that obtained in a recent position space analysis of the static potential based on the same lattice data. Our final results are r0 ΛMS(nf=2)=0.692(31) and ΛMS(nf=2)=331(21) MeV.