Undergraduate Research at Jefferson Lab

Proton Radius from Classic Electron Data

Student: Ethan Buck

School: College of William and Mary

Mentored By: Douglas Higinbotham

With an electron accelerator, the charge radius of the proton is determined by elastically scattering electrons from protons. This type of scattering experiment determines the charge and magnetic structure, or form factor, of the proton as a function of the four-momentum transferred to the proton. By determining the slope of the form factors as Q² goes to 0, one can calculate the radius of the proton. The focus of this project is to review classic and modern electron scattering data to attempt to understand the discrepancy with the muonic Lamb shift results. Classic F test as well as the modern Akaike Information Criteria were used to select the most appropriate statistical models. Here we show that both the classic and modern data are actually rather consistent with the muonic Lamb shift radius of 0.84 fm.