First determination of generalized polarizabilities of the proton by a virtual compton scattering experiment
Absolute differential cross sections for the reaction ep-->epgamma have been measured at a four-momentum transfer with virtuality Q2 = 0.33 GeV2 and polarization epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum of the outgoing photon in the photon-proton center of mass frame. The experiment has been performed with the high-resolution spectrometers at the Mainz Microtron MAMI. From the photon angular distributions, two structure functions which are a linear combination of the generalized polarizabilities have been determined for the first time.
Roche
J
CEA Saclay, DSM/DAPNIA/SPhN, 91191 Gif-sur-Yvette Cedex, France.
Friedrich
JM
Lhuillier
D
Bartsch
P
Baumann
D
Berthot
J
Bertin
PY
Breton
V
Boeglin
WU
Bohm
R
D'Hose
N
Derber
S
Degrande
N
Ding
M
Distler
MO
Ducret
JE
Ewald
I
Fonvieille
H
Friedrich
J
Guichon
PA
Holvoet
H
Hyde-Wright
CE
Jennewein
P
Kahrau
M
Kerhoas
S
Krygier
KW