First measurement of proton's charge form factor at very low $Q^2$ with initial state radiation
Résumé
We report on a new experimental method based on initial-state radiation (ISR) in e – p scattering, which exploits the radiative tail of the elastic peak to study the properties of electromagnetic processes and to extract the proton charge form factor ( GEp ) at extremely small Q2 . The ISR technique was implemented in an experiment at the three-spectrometer facility of the Mainz Microtron (MAMI). This led to a precise validation of radiative corrections far away from elastic line and provided first measurements of GEp for 0.001≤Q2≤0.004(GeV/c)2 .
Mots clés
12.20.-m
25.30.Bf
41.60.-m
Initial state radiation
Proton
Form factor
Radiative corrections
form factor: charge
p: charge
radiation: initial-state interaction
electron p: scattering
Lamb shift
Bethe-Heitler
elastic scattering
beam: current
spectrometer
microtron
Mainz Linac
experimental methods
numerical calculations
experimental results