Double spin asymmetry in exclusive ρ 0 muoproduction at COMPASS

The longitudinal double spin asymmetry A1 ρ for exclusive leptoproduction of ρ0 mesons, μ+N→μ+N+ρ, is studied using the COMPASS 2002 and 2003 data. The measured reaction is incoherent exclusive ρ0 production on polarised deuterons. The Q2 and x dependence of A1 ρ is presented in a wide kinematical range, 3×10-3x<3×10-3). The asymmetry is in general compatible with zero in the whole kinematical range.