Double-spin asymmetries in the cross section of electroproduction of ρ0 and φ mesons on the proton and deuteron are measured at the HERMES experiment. The photoabsorption asymmetry in exclusive ρ0 electroproduction on the proton exhibits a positive tendency. This is consistent with theoretical predictions that the exchange of an object with unnatural parity contributes to exclusive ρ0 electroproduction by transverse photons. The photoabsorption asymmetry on the deuteron is found to be consistent with zero. Double-spin asymmetries in ρ0 and φ meson electroproduction by quasi-real photons were also found to be consistent with zero; the asymmetry in the case of the φ meson is compatible with a theoretical prediction which involves ss̄ knockout from the nucleon.
ASJC Scopus subject areas
- Engineering (miscellaneous)
- Physics and Astronomy (miscellaneous)