Flat transverse momentum dependence of the single-spin asymmetry in inclusive neutral pion production

Abstract

We discuss recent experimental results from the Relativistic Heavy Ion Collider where the flat transverse momentum dependence of a single-spin asymmetry has been found in the inclusive production of neutral pions. This dependence takes place in a wide region of the transverse momenta up to p T ¼ 10 GeV=c. We emphasize that similar dependence has been predicted in the nonperturbative spin filtering mechanism for the single-spin asymmetries in hadron interactions and present some implications for this mechanism from the new experimental data.

Spin Experimentation with Unpolarized Colliding Beams at the LHC

“…The numerical value of the polarization P Λ can be significant; there are no small factors in (5). We use the model from [18] in which M is proportional to two nucleon masses, the value of parameter ζ 2, and r f lip U→S 0.1-0.2 fm. The above qualitative features of the dependence of polarization on x F , p ⊥ , and energy are in good agreement with the experimentally observed trends [3].…”