Structure In The Proton Form Factor Ratio at Low Q$^2$

ORAL

Abstract

Double polarization asymmetry measurements are allowing the electric to magnetic form factor ratios be determined with unprecedented precision. New results from BLAST and, more recently, from Jefferson Lab indicate that there is an unexpected dip in the proton form factor ratio around a Q$^2$ of 0.3 GeV$^2$. This structure at low Q$^2$ may provide new insight into of the peripheral substructure of the proton. The Jefferson Lab data, which was taken in less than two days as part of a calibration measurement, will be presented along with the expected uncertainties, in the Q$^2$ range from 0.25 to 0.7 GeV$^2$, which would be achieved with a dedicated experiment.

Authors

  • Douglas Higinbotham

    Jefferson Lab