Spin Density Matrix Elements from diffractive $\varphi$ meson production at HERMES

HERMES Collaboration, W. Augustyniak, A. Borissov +1

Exclusive production of $\varphi$ mesons on hydrogen and deuterium targets is studied in the HERMES kinematic region $1<Q^2<7$ GeV${}^2$ and $3.0<W<6.3$ GeV. Spin density matrix…