Transverse single spin asymmetry in direct photon production in polarized pA collisions

Abstract

We study the transverse single spin asymmetry in direct photon production in pA collisions with incoming protons being transversely polarized. To facilitate the calculation, we formulate a hybrid approach in which the nucleus is treated in the Color Glass Condensate (CGC) framework while the collinear twist-3 formalism is applied on the proton side. It has been found that an additional term which arises from color entanglement shows up in the spin dependent differential cross section. The fact that this additional term is perturbatively calculable allows us to quantitatively study color entanglement effects.

20 pages, 6 figures, a few typos corrected, v3

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Cited by in corpus (9)

• Transverse single-spin asymmetries in $p^{\uparrow }p\to \gamma X$ from quark-gluon-quark correlations in the proton
• Single spin asymmetry in forward $pA$ collisions II: Fragmentation contribution
• Transverse spin observables in hard-scattering hadronic processes within collinear factorization
• Color entanglement for $\gamma$-jet production in polarized pA collisions
• Transverse single-spin asymmetries in proton-proton collisions at the AFTER@LHC experiment
• On the odderon mechanism for transverse single spin asymmetry in the Wandzura-Wilczek approximation
• Color entanglement effect in collinear twist-3 factorization
• Transverse single-spin asymmetry of charged hadrons at forward and backward rapidity in polarized $p$+$p$, $p$+Al, and $p$+Au collisions at $\sqrt{s_{NN}}=200$ GeV}
• Single spin asymmetry in forward $pA$ collisions from Pomeron-Odderon interference