Nucleon strange electromagnetic form factors

We determine the strange electromagnetic form factors of the nucleon within the lattice formulation of quantum chromodynamics using simulations that include light, strange and charm quarks in the sea all tuned to their physical mass values. We employ state-of-the-art techniques to accurately extract the form factors for values of the momentum transfer square up to 0.8 GeV2. We find that both the electric and magnetic form factors are statistically nonzero. We obtain for the strange magnetic moment mu(s) = -0.017(4)(+1 0)(+5 0), the strange magnetic radius < r(M)(2)>(s) is = -0.015(9)(+3 0)(+4 0) fm(2), and the strange charge radius < r(E)(2)>(s) = -0.0048(6)(0 -8)(+12 0) fm(2), where the first error is statistical, and the second and third systematic.