Analyzing power of inclusive production of π+,π-, and K0S by polarized protons at 13.3 and 18.5 GeV/c

We have measured the analyzing power in π⁺, π^-, and K⁰_S production by a polarized proton beam at 13.3 and 18.5 GeV/c. The data cover the central and the beam fragmentation region, in the transverse-momentum range up to 2 GeV/c. The results indicate that sizable effects are present at high x_F and also persist into the hard-scattering region for K⁰_S and π⁺. A zero value of the analyzing power was observed for π^- production.