Speaker
Hayg Guler
(DESY)
Description
For the first time, azimuthal beam-spin asymmetries have been measured in electroproduction of a hard exclusive photon on nuclei ranging from Deuterium to Xenon. The data were accumulated by the HERMES experiment at HERA/DESY in the years 1996-2004 by scattering the 27.6 GeV lepton beam off an internal gas target. The asymmetries of the coherent and incoherent processes for D, 4He, N, Ne, Kr and Xe have been extracted and compared to the proton beam-spin asymmetry as a function of the Mandelstam variable $t$. The dependence on the atomic number $A$ of the ratio of the beam-spin asymmetry on nuclei to that on the proton is evaluated and compared to GPD model predictions.
Primary author
Hayg Guler
(DESY)
