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arXiv · 2107.10079

Transverse Single-Spin Asymmetries of Midrapidity Direct Photons and Neutral Mesons at PHENIX

Nicole Lewis
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Abstract

Results are presented for the transverse single-spin asymmetries of direct photons, neutral pions, and eta mesons for $|η|<0.35$ from $p^\uparrow + p$ collisions with $\sqrt{s} = 200$ GeV at PHENIX. As hadrons, $π^0$ and $η$ mesons are sensitive to both initial- and final-state effects and at midrapidity probe the dynamics of gluons along with a mix of quark flavors. Because direct photon production does not include hadronization, the direct photon TSSA is only sensitive to initial-state effects and at midrapidity provides a clean probe of the gluon dynamics in transversely polarized protons. All three of these results will help constrain the collinear twist-3 trigluon correlation function as well as the gluon Sivers function, improving our knowledge of spin-dependent gluon dynamics in QCD.

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Nicole Lewis. 2022-03-17. Transverse Single-Spin Asymmetries of Midrapidity Direct Photons and Neutral Mesons at PHENIX. https://arxiv.org/abs/2107.10079

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