Recent results of baryon EM form factors at BESIII

Abstract

Precise experimental measurements of the baryon form factors are a test-bed for understanding the baryon’s properties and dynamical behavior emerge from QCD. With high statistics, the cross section of e+e− → pp and e+e− → nn are both measured with the highest precision in a wide q2 range. The oscillation behavior on the proton and neutron effective form factor is updated with SND result. With the ISR technique, the form factor measurement can reach as low as the mass threshold of pp or nn. Analyticity of nucleon form factors is discussed. Moreover, new results about the hyperon (Λ, Λc, Σ, Ω, ∆) form factors are presented in this talk. Some similar behaviors appear on the hyperon form factors which will help to understand the internal structure or interactions inside of the baryon. The complete determination of EMFFs of Λ and Σ has been carried on and provides a new insight of EMFFs in time-like region.