Vector meson production from a polarized nucleon

Abstract

We provide a framework to analyze the electroproduction process ep -> ep rho with a polarized target, writing the angular distribution of the rho decay products in terms of spin density matrix elements that parameterize the hadronic subprocess gamma* p -> rho p. Using the helicity basis for both photon and meson, we find a representation in which the expressions for a polarized and unpolarized target are related by simple substitution rules.

Comments: 31 pages, 2 figures. v2: added section on non-resonant contributions