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RESEARCH PRODUCT
Nucleon electromagnetic form factors in two-flavor QCD
Benjamin JägerThomas RaeS. CapitaniM. Della MorteG. Von HippelDalibor DjukanovicB. KnippschildJ. HuaHarvey B. MeyerHartmut Wittigsubject
PhysicsQuantum chromodynamicsNuclear and High Energy PhysicsParticle physicsNuclear TheoryMagnetic momentHigh Energy Physics::LatticeHigh Energy Physics - Lattice (hep-lat)Momentum transferFOS: Physical sciencesFermionNuclear Theory (nucl-th)BaryonHigh Energy Physics - PhenomenologyHigh Energy Physics - LatticeHigh Energy Physics - Phenomenology (hep-ph)Charge radiusQuantum electrodynamicsEffective field theoryNucleondescription
We present results for the nucleon electromagnetic form factors, including the momentum transfer dependence and derived quantities (charge radii and magnetic moment). The analysis is performed using O(a) improved Wilson fermions in Nf=2 QCD measured on the CLS ensembles. Particular focus is placed on a systematic evaluation of the influence of excited states in three-point correlation functions, which lead to a biased evaluation, if not accounted for correctly. We argue that the use of summed operator insertions and fit ans\"atze including excited states allow us to suppress and control this effect. We employ a novel method to perform joint chiral and continuum extrapolations, by fitting the form factors directly to the expressions of covariant baryonic chiral effective field theory. The final results for the charge radii and magnetic moment from our lattice calculations include, for the first time, a full error budget. We find that our estimates are compatible with experimental results within their overall uncertainties.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-04-17 | Physical Review D |