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arXiv · hep-lat/9605033

Alpha_s from the non-perturbatively renormalised lattice three-gluon vertex

B. Alles·D. S. Henty·H. Panagopoulos·C. Parrinello·C. Pittori·D. G. Richards
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Abstract

We compute the running QCD coupling on the lattice by evaluating two-point and three-point off-shell gluon Green's functions in a fixed gauge and imposing non-perturbative renormalisation conditions on them. Our exploratory study is performed in the quenched approximation at beta=6.0 on 16^4 and 24^4 lattices. We show that, for momenta in the range 1.8-2.3 Gev, our coupling runs according to the two-loop asymptotic formula, allowing a precise determination of the corresponding Lambda parameter. The role of lattice artifacts and finite-volume effects is carefully analysed and these appear to be under control in the momentum range of interest. Our renormalisation procedure corresponds to a momentum subtraction scheme in continuum field theory, and therefore lattice perturbation theory is not needed in order to match our results to the MSbar scheme, thus eliminating a major source of uncertainty in the determination of alpha_MSbar. Our method can be applied directly to the unquenched case.

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BibTeXRIS

B. Alles, D. S. Henty, H. Panagopoulos, C. Parrinello, C. Pittori, D. G. Richards. 1997-06-08. Alpha_s from the non-perturbatively renormalised lattice three-gluon vertex. https://doi.org/10.1016/s0550-3213(97)00483-5

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