Separated cross-sections in pi0 electroproduction at threshold at Q**2 = 0.05-GeV**2/c**2
Eur.Phys.J.A 38 (2008) 27-33, 2008.
Mainz Microtron MAMI. Measurement of the separated cross sections SIG(C=T) + EPS*SIG(C=L), SIG(C=LT) and SIG(C=TT) for PI0 electroproduction from the proton from threshold to additional centre-of-mass energy of 40 MeV. The data are at a photon Q**2 of 0.05 GeV**2 and centre-of-mass angle of 90 degrees. The beam helicity asymmetry ASYM(C=LTP) is also determined, defined as (SIG(+)-SIG(-))/(SIG(+)+SIG(-)) where SIG(+) and (-) are the differential cross sections for PHI of 90 degrees with beam polarization parallel and anti-parallel to the beam direction. PHI is the angle between the scattering and production planes.