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

TL;DR

This study compares the analyzing power in polarized proton and pion-induced reactions at high energies, revealing contrasting behaviors in the central region but similar results in the fragmentation region, supported by new and previous data.

Contribution

It provides new measurements of the analyzing power at 50 GeV/c, confirming previous findings and highlighting the differing behaviors in the central region versus the fragmentation region.

Findings

$A_N$ behaves differently in the central region for the two reactions.

$A_N$ in the fragmentation region is similar for both reactions.

New data at 50 GeV/c supports previous results at 70 GeV/c.

Abstract

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.