Nucleon structure from Lattice QCD using a nearly physical pion mass

作者：Green J R; Engelhardt M; Krieg S; Negele J W; Pochinsky A V; Syritsyn S N^*

来源：Physics Letters B, 2014, 734: 290-295.

DOI：10.1016/j.physletb.2014.05.075

• Lattice QCD
• Nucleon structure
• Form factors

We report the first Lattice QCD calculation using the almost physical pion mass m(pi) = 149MeVthat agrees with experiment for four fundamental isovector observables characterizing the gross structure of the nucleon: the Dirac and Pauli radii, the magnetic moment, and the quark momentum fraction. The key to this success is the combination of using a nearly physical pion mass and excluding the contributions of excited states. An analogous calculation of the nucleon axial charge governing beta decay has inconsistencies indicating a source of bias at low pion masses not present for the other observables and yields a result that disagrees with experiment.

• 出版日期2014-6-27