Measurements of Multiparticle Correlations in d + Au Collisions at 200, 62.4, 39, and 19.6 GeV and p + Au Collisions at 200 GeV and Implications for Collective Behavior

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Recently, multiparticle-correlation measurements of relativistic p/d/3He+Au, p+Pb, and even p+pcollisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two-, four-, and six-particle angular correlations in d+Au collisions at √sNN=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Aucollisions at √sNN=200  GeV. We find the four-particle cumulant to be real valued for d+Aucollisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.

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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.