Speaker
Doris Jakubassa
(University of Munich)
Description
The beam-normal spin asymmetry for positrons scattering from the spin-zero nuclei $^{12}$C and $^{208}$Pb in the energy region below the pion production threshold is calculated by means of the phase-shift analysis, and its corrections from dispersion and from the QED effects are estimated.
For $^{12}$C both effects can be of comparable magnitude, typically in the percent region, but they decrease with energy above 70 MeV at backward angles.
For $^{208}$Pb the QED effects, amounting up to 10\% near 120 MeV, exceed largely the dispersive correction.
Both types of corrections are often much larger for positrons than the corresponding ones for electron impact.
Author
Doris Jakubassa
(University of Munich)
