Polarization in Hyperon Photo- and Electro- Production
Abstract
Description
Multiple polarization observables must be measured to access the amplitude structure of pseudoscalar meson photoproduction off the proton. The hyperon-producing reactions are especially attractive to study, since the weak decays allow straightforward measurement of the induced and recoil polarization observables. In this paper we emphasize $γ+ p \to K^+ + Λ$, discussing recent measurements of $C_x$, $C_z$, and $P$ for this reaction. An empirical constraint on the helicity amplitudes is obtained. A simplified model involving spin-flip and spin non-flip amplitudes is presented. Finally, a semi-classical model of how the polarization may arise is presented.
Invited paper at NStar2007, Accepted for EPJ A 1-21-08, 6 pages, 6 figures
Invited paper at NStar2007, Accepted for EPJ A 1-21-08, 6 pages, 6 figures