last update : 01-15-07
This page is a summary of the research I did for my Phd.
Compton Scattering (VCS) of
below pion threshold :
The scattering of a photon off a proton allows the
of the rigidity of the internal structure of the nucleon. It is a
process as the shape of the proton (as measured with the nucleon form
is modified under the influence of the scattered photon. Below pion
threshold (but arbitrary squared quadri-momentum transfer of the
photon), the measured observables are the Generalized Polarizabilities
(GP). They generalize the concept of electric and magnetic
measured in Real Compton Scattering. Between 1995 and 1998 we have
the absolute unpolarized cross-sections for the photon
off the Proton with the three-Spectrometer-Setup at MAMI
(Mainz, Germany) at a momentum transfer of 0.33 GeV2/c2
and a virtual photon polarization of 0.62. We extracted two
of the generalized polarizabilities and compared them to theoretical
of the non perturbative structure of the nucleon. Our experiment at
was the first precise measurement of the photon electro production to
carried on, thanks to the advance of the CW beam delivery technology.
that time, similar experiments have been performed at JLab/Hall A and
The advance of the theoretical formalism allows also to measure the GP
in the Delta region where the effect is larger.
- PRL 85,
: "The First determination of generalized polarizabilities of the
by Virtual Compton Scattering experiment ", J. Roche at al.
- My thesis write-up (in French,
careful it is
- This research
topic was my PhD thesis subject. For this project
at the SPhN/CEA/Saclay
under the direction of N. D'Hose while being a student registered at
B. Pascal (France) .