A new scaling law for analyzing power in hadron production by transversely polarized baryons

Experimental data on analyzing power for inclusive meson and baryon production in collisions of transversely polarized protons and antiprotons with protons and light nuclei have been analyzed. It is found that the existing data can be described by a simple function of collision energy (\(\sqrt{s}\)), transverse momentum (\(p_{\mathrm{T}}{}\)) and a new scaling variable \(x_{\mathrm{A}}{} = E/E^{\mathrm{BEAM}}{}\). At beam energies above 40 GeV and \(p_{\mathrm{T}}{}\) above 1.0 GeV/c the analyzing power is described by a function of \(x_{\mathrm{A}}{}\) and \(p_{\mathrm{T}}{}\) only (\(A_{\mathrm{N}}{}={\mathrm{F} }(p_{\mathrm{T}} {}){\mathrm{G} }(x_{\mathrm{A}}{})\)) for both polarized proton fragmentation and central regions of proton-hadron collision. Comparison of data from Fermilab and new IHEP data measured using 40 GeV/c polarized proton beam was most decisive for the revelation of the above regularities. This new scaling law allows one to predict the analyzing powers for kinematic regions, not yet explored in experiments and constrains models of strong interactions. The new scaling law allows one also to use some reactions as polarimeters for experiments with a polarized beam.