Single spin asymmetry in forward $pA$ collisions II: Fragmentation contribution

Abstract

We compute the twist-three fragmentation contribution to the transverse single spin asymmetry (SSA) in light hadron production $p^{\uparrow }p\to hX$ and $p^{\uparrow }A\to hX$ including the gluon saturation effect in the unpolarized nucleon/nucleus. Together with the results in our previous paper, this completes the full evaluation of the SSA in this process in the "hybrid" formalism. We argue that the dependence of SSAs on the atomic mass number in the forward region can elucidate the relative importance of the soft gluon pole contribution from the twist-three quark-gluon-quark correlation in the polarized nucleon and the twist-three fragmentation contribution from the final state hadron.

11 pages, 2 figures

References in corpus (4)

• Towards an explanation of transverse single-spin asymmetries in proton-proton collisions: the role of fragmentation in collinear factorization
• The RHIC SPIN Program: Achievements and Future Opportunities
• Transverse single spin asymmetry in direct photon production in polarized pA collisions
• Transverse spin observables in hard-scattering hadronic processes within collinear factorization

Cited by in corpus (4)

• T-odd Leading-Twist Quark TMDs at Small $x$
• Single-spin asymmetries at two loops
• 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
• Color entanglement effect in collinear twist-3 factorization