Polarization phenomena in elastic scattering, for axial parametrization of two-photon exchange

✍ Scribed by M.P. Rekalo; E. Tomasi-Gustafsson

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 221 KB
• Volume: 742
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2004.07.009

✦ Synopsis

We analyze polarization phenomena for elastic lepton-nucleon scattering, parametrizing the 2γexchange contribution, as the product of lepton and nucleon axial vector currents, that correspond to C = +1 exchange in the annihilation channel. We found two combinations of polarization observables (one for three T-odd observables and another one for five T-even observables, which allow to measure the ratio G E (Q 2 )/G M (Q 2 ) of nucleon electromagnetic form factors in model-independent way, without any specific assumption about the 2γ -exchange mechanism. Both these important combinations have a general character and do not depend on the choice of the spin structure for the 2γ -exchange.