Goy, J.Furget, C.Kox, S.Pastor, A.Real, J.S.Arvieux, J.Beise, E.J.Bimbot, L.Brash, E.Breuer, H.Collins, G.Duncan, F.Ducret, J.E.Garçon, M.Gilmas, R.Glashausser, C.Ladygine, V.P.Morlet, M.Merchez, F.Rutt, P.Tomasi-Gustaffson, E.Voutier, E.The analyzing power Ay0 of the reaction H(p⃗,d)π+ has been measured at a fixed value of the Mandelstam variable ud=-0.17GeV2 for nine proton energies between 1000 and 1300 MeV. The experiment was performed at SATURNE with the SPES1 spectrometer. The data exhibit structure around √s≃2.37GeV. The origin of this structure could be related to a resonancelike behavior of the 1S0P or 1G4F partial amplitudes.PhysicsMandelstam variableArticle