Spin asymmetries in exclusive ϱ, Φ, and Jψ production at HERMES Original Research Article

Double-spin asymmetries in exclusive ϱ, Φ, and View the MathML source production in longitudinally polarised lepton-nucleon scattering have been measured at the HERMES experiment, using the 1996–1997 data on the polarised hydrogen target. The analysis is focused on the ϱ meson and a significant positive asymmetry A1ϱ was found. Much smaller Φ and View the MathML source data samples show asymmetries consistent with zero.