1201.6114 (J. M. M. Hall et al.)

Chiral extrapolations for nucleon magnetic moments    [PDF]

J. M. M. Hall, D. B. Leinweber, R. D. Young

Lattice quantum chromodynamics (QCD) simulations have made significant
progress in the calculation of nucleon electromagnetic form factors in the
chiral regime in recent years. With simulation results achieving pion masses of
order ~180 MeV, there is an apparent challenge as to how the physical regime is
approached. By using contemporary methods in chiral effective field theory,
both the quark-mass and finite-volume dependence of the isovector nucleon
magnetic moment are carefully examined. The extrapolation to the physical point
yields a result that is compatible with experiment, albeit with a combined
statistical and systematic uncertainty of 10%. The extrapolation shows a strong
finite-volume dependence; lattice sizes of L > 5 fm must be used to simulate
results within 2% of the infinite-volume result for the magnetic moment at the
physical pion mass.

View original: http://arxiv.org/abs/1201.6114