Aug 4 – 8, 2015
America/Detroit timezone

Model Independent Analysis of the Proton Magnetic Radius

Aug 6, 2015, 2:00 PM
Room 4 (Michigan League)

Room 4

Michigan League

QCD Theory QCD and Heavy Ions


Joydeep Roy (Wayne State University)


The Proton is a fundamental constituent of matter. In contrast to other fundamental particles like the electron, it is an extended object and has a finite size that can be inferred with some degree of accuracy from several measurements. The electric radius can be extracted from electron-proton scattering experiments,(r_E^p=0.871±0.009 fm) and Lamb shift in Muonic Hydrogen (r_E^p=0.84184±0.0006 fm). The reason for the discrepancy between these values is still unknown. In the literature there also exist several values of the proton magnetic radius extracted using several model-dependent methods. We use constraints from the analytic behavior of the form factors to determine the proton magnetic radius in a model-independent way. Using existing datasets of electron-proton scattering we find r_M^p=〖0.91〗_(-0.06)^(+0.03)±0.02 fm. When we include electron-neutron scattering data and pion data, we find r_M^p=〖0.87〗_(-0.05)^(+0.04)±0.01 fm and r_M^p=〖0.87〗_(-0.02)^(+0.02) fm respectively. We also extracted the neutron magnetic radius as r_M^n=〖0.89〗_(-0.03)^(+0.03) fm combining all three datasets.
Oral or Poster Presentation Oral

Primary author

Joydeep Roy (Wayne State University)

Presentation materials