2000/04/18 by A. Hart, UKQCD Collaboration, Hart, A. +2
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #hep-lat #hep-ph #hep-th
paper · pdf · doi:10.48550/arxiv.hep-ph/0004180
18 pp of LaTeX. No change to content between versions. Talk presented at the IoP Particle Physics 2000 conference in Edinburgh. Not for publication; superceded by our paper hep-lat/0108006
arxiv created 2001/08/08 · arxiv updated 2009/11/30
We study the topological susceptibility, chi, in QCD with two quark flavours using the lattice field configurations recently produced by the UKQCD collaboration. We find clear evidence for the expected suppression at small quark mass, and examine the variation of chi with this mass. The resulting estimate of the pion decay constant, fpi = 105 +/- 5 +18/-10 MeV, is consistent with the experimental value of approximately 93 MeV. We compare chi to the large-Nc prediction and find consistency over a large range of quark masses. The benefits of the non-perturbative action improvement scheme and the matched lattice spacings between simulation ensembles are discussed. We compare our results with other studies and suggest a reason why such a quark mass dependence has not been previously seen.