May 29, 2018 to June 3, 2018
Hyatt Regency Indian Wells Conference Center
US/Pacific timezone

Data Analysis and Preliminary Results of the Proton Charge Radius Experiment (PRad) at JLab

Jun 2, 2018, 5:10 PM
South Foyer | Nopales Room (Hyatt Regency Indian Wells Conference Center)

South Foyer | Nopales Room

Hyatt Regency Indian Wells Conference Center

44600 Indian Wells Lane, Indian Wells, CA 92210, USA


Weizhi Xiong (Duke University)


In order to investigate the proton radius puzzle, the PRad experiment (E12-11-106) [1] was performed in 2016 in Hall B at Jefferson Lab, with both 1.1 and 2.2 GeV unpolarized electron beams. The experiment aims to measure the $e$-$p$ elastic scattering cross section at unprecedented low values of the momentum transfer squared region ($Q^2 = 2\times10^{-4} - 0.06$ (GeV/c)$^2$), with a sub-percent precision. The PRad experiment utilizes a non-magnetic calorimetric method with a large acceptance and high resolution calorimeter (HyCal), and two large area, high spatial resolution Gas Electron Multiplier (GEM) detectors. To have a better control over the systematic uncertainties, the absolute $e$-$p$ elastic scattering cross section is normalized to that of the well-known Moller scattering process, which is measured simultaneously within similar kinematics and geometrical acceptances. The windowless H$_2$-gas-flow target utilized in the experiment largely removes a typical background source, the target cell windows. In this talk, we will discuss details of the data analysis and present preliminary results from both beam energy settings. [1] Spokespersons: A. Gasparian (contact), H. Gao, M. Khandaker, D. Dutta.
E-mail [email protected]
Collaboration name PRad Collaboration
Funding source Supported in part by the U.S. Department of Energy under Contract No. DE-FG02-03ER41231, NSF MRI award PHY-1229153

Primary author

Weizhi Xiong (Duke University)


Mr Chao Peng (Duke University)

Presentation materials