Extraction of Proton Electric Form Factor and Radius from Low Transfer Momentum Data

A precise measurement of the proton’s electric form factor at low transfer momentum Q 2 provides a tight constraint in determining the proton charge radius. In this work the electric form factor is obtained using phenomenological quark-based model and compared with low-Q 2 elastic electron–proton scattering data. The calculated electric form factor agrees with experimental data at Q 2 < 0.1GeV 2 , while deviations at Q 2 above 0.1GeV 2 indicate limitations of the model when applied beyond the low-Q 2 domain. Using polynomial based parametrization, the average value of the obtained proton radius is around 0.83 fm which is consistent with PRad and spectroscopy experiments, supporting a smaller proton charge radius.