PHENIX Spin Physics Overview

Authors

  • Dillon S. Fitzgerald University of Michigan

DOI:

https://doi.org/10.31349/SuplRevMexFis.3.040908

Keywords:

PHENIX, spin physics, spin asymmetries, longitudinal double-spin asymmetries, transverse single-spin asymmetries, direct photons, heavy flavor, charged pions, neutral mesons, jets, neutrons, gluon helicity, trigluon correlators

Abstract

Understanding the spin structure of the proton is of large interest to the nuclear physics community and it is one of the main goals of the spin physics program at the Relativistic Heavy Ion Collider (RHIC). Measurements from data taken by the PHENIX detector with transverse (p ↑ + p, p ↑ + Al, p ↑ + Au) and longitudinal (⃗p + ⃗p) proton polarization play an important role in this, in particular due to the leading order access to gluons in polarized protons. This is a crucially important counterpart to measurements made in lepton-hadron scattering experiments where gluons are not accessible at leading order. Transverse spin asymmetries provide insight into initial and final-state spinmomentum and spin-spin parton-hadron correlations, while longitudinal spin asymmetries provide access to parton polarization. A number of important recent PHENIX results and ongoing analyses will be presented, along with a discussion of how these measurements contribute to our understanding of proton spin structure.

References

M. G. Alekseev et al., Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering, Phys. Lett. B 693 (2010) 227, 10.1016/j.physletb.2010.08.034

A. Airapetian et al., Quark helicity distributions in the nucleon for up, down, and strange quarks from semi-inclusive deep-inelastic scattering, Phys. Rev. D 71 (2005) 012003, 10.1103/PhysRevD.71.012003

H. Avakian et al., Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target, Phys. Rev. Lett. 105 (2010) 262002, 10.1103/PhysRevLett.105.262002

D. de Florian, et al., Evidence for Polarization of Gluons in the Proton, Phys. Rev. Lett. 113 (2014) 012001, 10.1103/PhysRevLett.113.012001

G. L. Kane, J. Pumplin, and W. Repko, Transverse Quark Polarization in Large-pT Reactions, e +e − Jets, and Leptoproduction: A Test of Quantum Chromodynamics, Phys. Rev. Lett. 41 (1978) 1689, 10.1103/PhysRevLett.41.1689

S. Benic, et al., Single-spin asymmetries at two loops, Phys. Rev. D 100 (2019) 094027, 10.1103/PhysRevD.100.094027

C. A. Aidala, et al., The spin structure of the nucleon, Rev. Mod. Phys. 85 (2013) 655, 10.1103/RevModPhys.85.655

R. D. Klem, et al., Measurement of Asymmetries of Inclusive Pion Production in Proton Proton Interactions at 6-GeV/c and 11.8-GeV/c, Phys. Rev. Lett. 36 (1976) 929, 10.1103/PhysRevLett.36.929

D. L. Adams et al., Analyzing power in inclusive π + and π − production at high xF with a 200-GeV polarized proton beam, Phys. Lett. 264 (1991) 462, 10.1016/0370-2693(91)90378-4

C. Allgower et al., Measurement of analyzing powers of π + and π − produced on a hydrogen and a carbon target with a 22- GeV/c incident polarized proton beam, Phys. Rev. D 65 (2002) 092008, 10.1103/PhysRevD.65.092008

I. Arsene et al., Single Transverse Spin Asymmetries of Identified Charged Hadrons in Polarized p + p Collisions at √ s = 62.4 GeV, Phys. Rev. Lett. 101 (2008) 042001, 10.1103/PhysRevLett.101.042001

X. Ji, et al., A Unified picture for single transverse-spin asymmetries in hard processes, Phys. Rev. Lett. 97 (2006) 082002, 10.1103/PhysRevLett.97.082002

J. P. Ralston and D. E. Soper, Production of dimuons from high-energy polarized proton-proton collisions, Nuclear Physics B 152 (1979) 109, https://doi.org/10.1016/0550-3213(79)90082-8

D. Sivers, Single-spin production asymmetries from the hard scattering of pointlike constituents, Phys. Rev. D 41 (1990) 83, 10.1103/PhysRevD.41.83

D. Boer and P. J. Mulders, Time-reversal odd distribution functions in leptoproduction, Phys. Rev. D 57 (1998) 5780, 10.1103/PhysRevD.57.5780

J. Collins, Fragmentation of transversely polarized quarks probed in transverse momentum distributions, Nuclear Physics B 396 (1993) 161, https://doi.org/10.1016/0550-3213(93)90262-N

K. Adcox et al., PHENIX detector overview, Nucl. Instrum. Meth. A 499 (2003) 469, 10.1016/S0168-9002(02)01950-2

J. Adam et al., Longitudinal double-spin asymmetry for inclusive jet and dijet production in pp collisions at √ s = 510 GeV, Phys. Rev. D 100 (2019) 052005, 10.1103/PhysRevD.100.052005

U. A. Acharya et al., Measurement of charged pion double spin asymmetries at midrapidity in longitudinally polarized p + p collisions at √ s = 510 GeV, Phys. Rev. D 102 (2020) 032001, 10.1103/PhysRevD.102.032001

A. Adare et al., Inclusive cross section and double-helicity asymmetry for π 0 production at midrapidity in p + p collisions at √ s = 510 GeV, Phys. Rev. D 93 (2016) 011501, 10.1103/PhysRevD.93.011501

A. Adare et al., Charged-pion cross sections and doublehelicity asymmetries in polarized p+p collisions at √ s=200 GeV, Phys. Rev. D 91 (2015) 032001, 10.1103/PhysRevD.91.032001

U. A. Acharya et al., Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at √ s = 510 GeV in ⃗p + ⃗p Collisions (2022)

G. Bunce, et al., Proposal on spin physics using the RHIC polarized collider (1992), 10.2172/1151313

G. Bunce, et al., Prospects for spin physics at RHIC, Ann. Rev. Nucl. Part. Sci. 50 (2000) 525, 10.1146/annurev.nucl.50.1.525

U. A. Acharya et al., Transverse-single-spin asymmetries of charged pions at midrapidity in transversely polarized p+p collisions at √ s = 200 GeV, Phys. Rev. D 105 (2022) 032003, 10.1103/PhysRevD.105.032003

U. A. Acharya et al., Transverse single-spin asymmetries of midrapidity π 0 and η mesons in polarized p + p collisions at √ s = 200 GeV, Phys. Rev. D 103 (2021) 052009, 10.1103/PhysRevD.103.052009

A. Adare et al., Measurement of transverse-single-spin asymmetries for midrapidity and forward-rapidity production of hadrons in polarized p+p collisions at √ s =200 and 62.4 GeV, Phys. Rev. D 90 (2014) 012006, 10.1103/PhysRevD.90.012006

U. D’Alesio, et al., Unraveling the Gluon Sivers Function in Hadronic Collisions at RHIC, Phys. Rev. D 99 (2019) 036013, 10.1103/PhysRevD.99.036013

H. Beppu, et al., Three-gluon contribution to the single spin asymmetry for light hadron production in pp collision, Phys. Rev. D 89 (2014) 034029, 10.1103/PhysRevD.89.034029

U. A. Acharya et al., Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p↑+p Collisions at s=200 GeV, Phys. Rev. Lett. 127 (2021) 162001, 10.1103/PhysRevLett.127.162001

D. L. Adams et al., Measurement of single spin asymmetry for direct photon production in p p collisions at 200-GeV/c, Phys. Lett. B 345 (1995) 569, 10.1016/0370-2693(94) 01695-9

H. Beppu, et al., Three-gluon contribution to the single spin asymmetry for light hadron production in pp collision, Phys. Rev. D 89 (2014) 034029, 10.1103/PhysRevD.89.034029

U. A. Acharya et al., Improving constraints on gluon spinmomentum correlations in transversely polarized protons via midrapidity open-heavy-flavor electrons in p ↑ + p collisions at √ s = 200 GeV (2022)

Z.-B. Kang, et al., Accessing tri-gluon correlations in the nucleon via the single spin asymmetry in open charm production, Phys. Rev. D 78 (2008) 114013, 10.1103/PhysRevD.78.114013

Y. Koike and S. Yoshida, Probing the three-gluon correlation functions by the single spin asymmetry in p ↑ p → DX, Phys. Rev. D 84 (2011) 014026, 10.1103/PhysRevD.84.014026

C. Aidala et al., Cross section and transverse single-spin asymmetry of muons from open heavy-flavor decays in polarized p+p collisions at √ s = 200 GeV, Phys. Rev. D 95 (2017) 112001, 10.1103/PhysRevD.95.112001

C. Aidala et al., Nuclear Dependence of the Transverse SingleSpin Asymmetry in the Production of Charged Hadrons at Forward Rapidity in Polarized p + p, p+Al, and p+Au Collisions at √sNN = 200 GeV, Phys. Rev. Lett. 123 (2019) 122001, 10.1103/PhysRevLett.123.122001

Z.-B. Kang and F. Yuan, Single Spin Asymmetry Scaling in the Forward Rapidity Region at RHIC, Phys. Rev. D 84 (2011) 034019, 10.1103/PhysRevD.84.034019

S. Benic and Y. Hatta, Single spin asymmetry in forward ´ pA collisions: Phenomenology at RHIC, Phys. Rev. D 99 (2019) 094012, 10.1103/PhysRevD.99.094012

U. A. Acharya et al., Transverse single spin asymmetries of forward neutrons in p + p, p+Al and p+Au collisions at √sNN = 200 GeV as a function of transverse and longitudinal momenta, Phys. Rev. D 105 (2022) 032004, 10.1103/PhysRevD.105.032004

G. Mitsuka, (private communication), based on [42]

G. Mitsuka, Recently measured large AN for forward neutrons in p ↑A collisions at √ sNN = 200 GeV explained through simulations of ultraperipheral collisions and hadronic interactions, Phys. Rev. C 95 (2017) 044908, 10.1103/PhysRevC.95.044908

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Published

2022-12-10

How to Cite

1.
Fitzgerald DS. PHENIX Spin Physics Overview. Supl. Rev. Mex. Fis. [Internet]. 2022 Dec. 10 [cited 2024 Apr. 25];3(4):040908 1-10. Available from: https://rmf.smf.mx/ojs/index.php/rmf-s/article/view/6829

Issue

Vol. 3 No. 4 (2022): Suplemento de la Revista Mexicana de Física. 37th Winter Workshop on Nuclear Dynamics

Section

09 37th Winter Workshop on Nuclear Dynamics

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Copyright (c) 2022 Dillon S. Fitzgerald (Author)

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