Pseudorapidity dependence of particle production and elliptic flow in asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^3He+Au at √(s__NN)=200 GeV

Asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^3He+Au at √(s__NN)=200 GeV provide an excellent laboratory for understanding particle production, as well as exploring interactions among these particles after their initial creation in the collision. We present measurements of charged hadron production dN_ ch/dη in all such collision systems over a broad pseudorapidity range and as a function of collision multiplicity. A simple wounded quark model is remarkably successful at describing the full data set. We also measure the elliptic flow v_2 over a similarly broad pseudorapidity range. These measurements provide key constraints on models of particle emission and their translation into flow.