Separation of the electric form factors GC and GQ of the deuteron at Q2=0.495 (GeV/c)2

Elastic electron deuteron scattering was measured at the Bonn 2.5 GeV Electron-Synchrotron using a unpolarized and a tensor polarized ND3 target. The scattered electrons and deuterons were detected in coincidence with two magnetic spectrometers. Data were taken at an average value of the four momentum transfer Q2=0.495 (GeV/c)2 in order to separate the electric monopole GC and the electric quadrupole form factor GQ of the deuteron. To have a sufficient control of systematic effects, both polarized and unpolarized cross sections were measured with an identical experimental set up. In the ratio R=(dσ/dΩ)pol/(dσ/dΩ)unp systematic effects are expected to cancel. This ratio R is related to the theoretical polarized cross section (dσ/dΩ)T here the spin quantization axis for the deuterons is orientated in the ed scattering plane, perpendicular to the virtual photon direction. A measurement of the ratio R provides information on the deuteron formfactors which is independent from unpolarized measurements. If one neglects the magnetic contributions, R is related to t20. (orig.)