Nucleon electromagnetic form factors from lattice QCD using a nearly physical pion mass

• Main Authors: Green, J. R (Contributor), Syritsyn, S. N (Author), Engelhardt, M. (Author), Krieg, Stefan F. (Author), Negele, John W. (Contributor), Pochinsky, Andrew (Contributor)
• Other Authors: Massachusetts Institute of Technology. Center for Theoretical Physics (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2014-10-21T19:43:15Z.
• Subjects: Article
• Online Access: Get fulltext

We present lattice QCD calculations of nucleon electromagnetic form factors using pion masses m[subscript π] = 149, 202, and 254 MeV and an action with clover-improved Wilson quarks coupled to smeared gauge fields, as used by the Budapest-Marseille-Wuppertal Collaboration. Particular attention is given to the removal of the effects of excited-state contamination by calculations at three source-sink separations and the use of the summation and generalized pencil-of-function methods. The combination of a calculation at the nearly physical mass m[subscript π] = 149  MeV in a large spatial volume (m[subscript π]L[subscript s] = 4.2) and the removal of excited-state effects yields agreement with experiment for the electric and magnetic form factors G[subscript E](Q[superscript 2]) and G[subscript M](Q[superscript 2]) up to Q[superscript 2] = 0.5  GeV[superscript 2].
United States. Dept. of Energy. Office of Nuclear Physics (Grant DE-FG02-94ER40818)