The nucleon axial charge from lattice QCD with controlled errors

S. Capitani, M. Della Morte, G. von Hippel, B. Jäger, A. Jüttner, B. Knippschild, H. B. Meyer, H. Wittig

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review


We report on our calculation of the nucleon axial charge gA in QCD with two flavours of dynamical quarks. A detailed investigation of systematic errors is performed, with a particular focus on contributions from excited states to three-point correlation functions. The use of summed operator insertions allows for a much better control over such contamination. After performing a chiral extrapolation to the physical pion mass, we find gA=1.223 +/- 0.063 (stat) +0.035 -0.060 (syst), in good agreement with the experimental value.
TidsskriftPhysical Review D
StatusUdgivet - 1. maj 2012

Bibliografisk note

6 pages, 5 figures, table and figure added, results and conclusions unchanged; version to appear in Physical Review D


  • hep-lat
  • hep-ph
  • nucl-th