Two-particle correlations in azimuthal angle and pseudorapidity in central $$^7\hbox {Be}+{}^9\hbox {Be}$$ 7 Be + 9 Be collisions at the CERN Super Proton Synchrotron

• Main Authors: A. Aduszkiewicz, E. V. Andronov, T. Antićić, V. Babkin, M. Baszczyk, S. Bhosale, A. Blondel, M. Bogomilov, A. Brandin, A. Bravar, W. Bryliński, J. Brzychczyk, M. Buryakov, O. Busygina, A. Bzdak, H. Cherif, M. Ćirković, M. Csanad, J. Cybowska, T. Czopowicz, A. Damyanova, N. Davis, M. Deliyergiyev, M. Deveaux, A. Dmitriev, W. Dominik, P. Dorosz, J. Dumarchez, R. Engel, G. A. Feofilov, L. Fields, Z. Fodor, A. Garibov, M. Gaździcki, O. Golosov, V. Golovatyuk, M. Golubeva, K. Grebieszkow, F. Guber, A. Haesler, S. N. Igolkin, S. Ilieva, A. Ivashkin, S. R. Johnson, K. Kadija, N. Kargin, E. Kashirin, M. Kiełbowicz, V. A. Kireyeu, V. Klochkov, V. I. Kolesnikov, D. Kolev, A. Korzenev, V. N. Kovalenko, S. Kowalski, M. Koziel, A. Krasnoperov, W. Kucewicz, M. Kuich, A. Kurepin, D. Larsen, A. László, T. V. Lazareva, M. Lewicki, K. Łojek, V. V. Lyubushkin, M. Maćkowiak-Pawłowska, Z. Majka, B. Maksiak, A. I. Malakhov, A. Marcinek, A. D. Marino, K. Marton, H.-J. Mathes, T. Matulewicz, V. Matveev, G. L. Melkumov, A. O. Merzlaya, B. Messerly, Ł. Mik, S. Morozov, S. Mrówczyński, Y. Nagai, M. Naskręt, V. Ozvenchuk, V. Paolone, O. Petukhov, R. Płaneta, P. Podlaski, B. A. Popov, B. Porfy, M. Posiadała-Zezula, D. S. Prokhorova, D. Pszczel, S. Puławski, J. Puzović, M. Ravonel, R. Renfordt, D. Röhrich, E. Rondio, M. Roth, B. T. Rumberger, M. Rumyantsev, A. Rustamov, M. Rybczynski, A. Rybicki, A. Sadovsky, K. Schmidt, I. Selyuzhenkov, A. Yu. Seryakov, P. Seyboth, M. Słodkowski, P. Staszel, G. Stefanek, J. Stepaniak, M. Strikhanov, H. Ströbele, T. Šuša, A. Taranenko, A. Tefelska, D. Tefelski, V. Tereshchenko, A. Toia, R. Tsenov, L. Turko, R. Ulrich, M. Unger, D. Uzhva, F. F. Valiev, D. Veberič, V. V. Vechernin, A. Wickremasinghe, Z. Włodarczyk, K. Wojcik, O. Wyszyński, E. D. Zimmerman, R. Zwaska, NA61/SHINE Collaboration
• Format: Article
• Language: English
• Published: SpringerOpen 2020-12-01
• Series: European Physical Journal C: Particles and Fields
• Online Access: https://doi.org/10.1140/epjc/s10052-020-08675-4

Abstract A measurement of charged hadron pair correlations in two-dimensional $$\Delta \eta \Delta \phi $$ Δ η Δ ϕ   space is presented. The analysis is based on total 30 million central Be + Be collisions observed in the NA61/SHINE detector at the CERN SPS for incident beam momenta of 19A, 30A, 40A, 75A, and 150A  $$\text {Ge} \text {V}/c$$ Ge / c . Measurements were carried out for unlike-sign and like-sign charge hadron pairs independently. The $$C(\Delta \eta ,\Delta \phi )$$ C ( Δ η , Δ ϕ ) correlation functions were compared with results from a similar analysis on p + p interactions at similar beam momenta per nucleon. General trends of the back-to-back correlations are similar in central Be + Be collisions and p + p interactions, but are suppressed in magnitude due to the increased combinatorial background. Predictions from the Epos and UrQMD models are compared to the measurements. Evolution of an enhancement around $$(\Delta \eta ,\Delta \phi ) = (0,0)$$ ( Δ η , Δ ϕ ) = ( 0 , 0 ) with incident energy is observed in central Be + Be collisions. It is not predicted by both models and almost non-existing in proton–proton collisions at the same momentum per nucleon.