New Polarization Program at U70 (SPASCHARM Project)

The new polarization program SPASCHARM is being prepared in Protvino. The program has two stages. The first stage is dedicated to single-spin asymmetries in the production of miscellaneous light resonances with the use of 34 GeV $pi^-$-beam. Inclusive and exclusive reactions will be studied simultaneously. The second stage is dedicated to single-spin and double-spin asymmetries in charmonium production with the use of 70 GeV polarized proton beam which will allow us to understand charmonium hadronic production mechanism and make gluon polarization $Delta g(x)$ extraction at large $x$.

The Comparative Study of the Inclusive $pi^0$ Analyzing Power in Reactions p+p(pol)->pi^0 + X and pi^-+p(pol)->pi^0 + X at 50 and 40 Gev/C Respectively

Single-spin asymmetries $A_N$ in reactions p+p(pol)->pi^0 + X and pi^-+p(pol)->pi^0 + X at 50 and 40 GeV/c respectively behave in drastically different ways in function of transverse momentum in the central region. At the same time $A_N$ in the polarized proton fragmentation region of these reactions are practically coinciding. Our new data on the analyzing power at 50 GeV/c in the polarized proton fragmentation region in reaction p+p(pol)->pi^0 + X confirm this conclusion with better statistics and coincide with our previous data at 70 GeV/c for the same reaction.