Measurement of emission angle anisotropy via long-range angular correlations with high $p_T$ hadrons in $d$$+$Au and $p$$+$$p$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV

• Main Authors: Alfred, M, Awes, T. C, Azmoun, B, Barish, K. N, Baumann, C, Berdnikov, A, Bok, J. S, Bumazhnov, V, Butsyk, S, Roman, V. Canoa, Caringi, A, Chiu, M, Choi, I. J, Choi, J. B, Danley, T. W, David, G, DeBlasio, K, Deshpande, A, Desmond, E. J, Drees, A, Franz, A, Glenn, A, de Cassagnac, R. Granier, Greene, S. V, Grim, G, Hamblen, J, Haslum, E, Hemmick, T. K, Hill, J. C, Hodges, A, Holzmann, W, Homma, K, Ichihara, T, Isenhower, D, Jacak, B. V, Jia, J, Jin, J, Joo, K. S, Kawall, D, Kim, E. -J, Kim, Y. -J, Koster, J, Král, A, Lee, K. B, Lee, S. H, Leite, M. A. L, Love, B, Maguire, C. F, Makek, M, Malik, M. D, Masui, H, McCumber, M, Meredith, B, Metzger, W. J, Mignerey, A. C, Mitsuka, G, Mohanty, A. K, Morino, Y, Morreale, A, Morrow, S. I. M, Nagai, K, Nakano, K, Nam, S, Nguyen, M, O'Brien, E, Oka, M, Ouchida, M, Pak, R, Papavassiliou, V, Park, I. H, Park, J. S, Park, S, Park, S. K, Peressounko, D. Yu, Proissl, M, Purschke, M. L, Radzevich, P. V, Reygers, K, Richford, D, Rosen, C. A, Ružička, P, Sakaguchi, T, Sako, H, Shigaki, K, Silvermyr, D, Singh, V, Sourikova, I. V, Stoll, S. P, Tanabe, R, Tanida, K, Tannenbaum, M. J, Ujvari, B, Vale, C, Virius, M, Wang, Z, Watanabe, Y, Wei, R, Wessels, J, Yamaura, K, Zajc, W. A
• Format: Journal Article
• Language: English
• Published: 24.11.2017
• Subjects: Physics - High Energy Physics - Experiment; Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.1711.09003

Phys. Rev. C 98, 014912 (2018) We present measurements of two-particle angular correlations between high-transverse-momentum ($2<p_T<11$ GeV/$c$) $\pi^0$ observed at midrapidity ($|\eta|<0.35$) and particles produced either at forward ($3.1<\eta<3.9$) or backward ($-3.7<\eta<-3.1$) rapidity in $d$$+$Au and $p$$+$$p$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV. The azimuthal angle correlations for particle pairs with this large rapidity gap in the Au-going direction exhibit a ridge-like structure that persists up to $p_T{\approx}6$ GeV/$c$ and which strongly depends on collision centrality, which is a similar characteristic to the hydrodynamical particle flow in A+A collisions. The ridge-like structure is absent in the $d$-going direction as well as in $p$$+$$p$ collisions, in the transverse-momentum range studied. The results indicate that the ridge-like structure is shifted in the Au-going direction toward more central collisions, similar to the charged-particle pseudorapidity distributions.