Double spin asymmetries ANN and ASS at s=200GeV in polarized proton-proton elastic scattering at RHIC

We present the first measurements of the double spin asymmetries ANN and ASS at s=200 GeV, obtained by the PP2PP experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). The data were collected in the four momentum transfer t range 0.01⩽|t|⩽0.03(GeV/c)2. The measured asymmetries, which are consistent with zero, allow us to estimate upper limits on the double helicity-flip amplitudes ϕ2 and ϕ4 at small |t| as well as on the difference ΔσT between the total cross sections for transversely polarized protons with antiparallel or parallel spin orientations.