Single-spin asymmetry for charged hadrons produced in proton-nucleus collisions at 40 GeV for c.m. production angles in the range 40°–79°

The transverse single-spin asymmetry for charged hadrons (π ±, K ±, p, $$\bar p$$ ) produced in proton-nucleus collisions was measured for c.m. production angles in the range 40°–79°. The measurements were performed with the FODS-2 setup by using a 40-GeV polarized proton beam originating from the accelerator of the Institute for High Energy Physics (Protvino) and hitting carbon and copper nuclear targets. The data in question were obtained in the polarized-proton-fragmentation region (0.0 < x F < 0.7, 0.6 < p T < 2.5 GeV/c). In agreement with data obtained at other energies, the single-spin asymmetry for π ± mesons is significant at high x F. For the first time, a sizable analyzing power, which changes sign at x F = 0.43, is observed for protons. The dependence of the analyzing power on the target-nucleus mass is insignificant.