Comparison of transverse single-spin asymmetries for forward ${\pi }^0$ production in polarized $pp$, $p\mathrm{Al}$ and $p\mathrm{Au}$ collisions at nucleon pair c.m. energy $\sqrt{s_{\mathrm{NN}}}=200$ GeV

STAR Collaboration, J. Adam, L. Adamczyk +358

The STAR Collaboration reports a measurement of the transverse single-spin asymmetries, $A_N$, for neutral pions produced in polarized proton collisions with protons ($pp$), with…