LAUSR

We study the production of prompt-photons at RHIC with a view to obtain information on the gluon Sivers function (GSF). At RHIC energy ($\sqrt{s}=200$ GeV), the Compton process, $gq\to\gamma q$ contributes significantly to the production of direct-photons at midrapidity and dominates it in the backwards (negative) rapdity region. We find that while the overall sizes of spin asymmetries are small, the gluon contribution can be significant in the neighbourhood of midrapidity, and further dominates in the moderate-to-highly backward region, $x_F\lesssim-0.3$. We find that the dominance of the asymmetries by the gluon contribution in the moderate-to-highly backward region increases further, on incorporation of the effects of the initial and final state interactions using the Colour-Gauge Invariant approach.