Single spin asymmetries in inclusive $\pi^0$ production in $p+p$ and   $\pi^-+p$ interactions at 40-70 GeV
  We present recent results of single-spin asymmetry $A_N$ measurements in $\pi^0$ inclusive production. Asymmetry was measured in $\pi^-p$ and $pp$ interactions at 40 and 70 GeV correspondingly. Significant asymmetry was observed in the polarized target fragmentation region. The results are in agreement with "universal threshold" of single-spin asymmetry. 
V.V. Mochalov, A.M.Davidenko, A.A.Derevschikov, Y.M.Goncharenko,   V.Y.Khodyrev, V.I.Kravtsov, Y.A.Matulenko, Y.M.Melnick, A...