Nonperturbative-transverse-momentum broadening in dihadron angular correlations in √sNN = 200 GeV proton-nucleus collisions

Aidala, C.
Apadula, Nicole
Hill, John
Hotvedt, Nels
Lajoie, John
Lebedev, Alexandre
Lee, S. H.
Ogilvie, Craig
Patel, Milap
Perry, Joshua
Rinn, Timothy
Rosati, Marzia
Runchey, Jonathan
Sen, Abhisek
Shimomura, M.
Timilsina, Arbin
et al.
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The PHENIX collaboration has measured high-pT dihadron correlations in p+p, p+Al, and p+Au collisions at √sNN=200 GeV. The correlations arise from inter- and intrajet correlations and thus have sensitivity to nonperturbative effects in both the initial and final states. The distributions of pout, the transverse-momentum component of the associated hadron perpendicular to the trigger hadron, are sensitive to initial- and final-state transverse momenta. These distributions are measured multidifferentially as a function of xE, the longitudinal momentum fraction of the associated hadron with respect to the trigger hadron. The near-side pout widths, sensitive to fragmentation transverse momentum, show no significant broadening between p+Au, p+Al, and p+p. The away-side nonperturbative pout widths are found to be broadened in p+Au when compared to p+p; however, there is no significant broadening in p+Al compared to p+p collisions. The data also suggest that the away-side pout broadening is a function of Ncoll, the number of binary nucleon-nucleon collisions, in the interaction. The potential implications of these results with regard to initial- and final-state transverse-momentum broadening and energy loss of partons in a nucleus, among other nuclear effects, are discussed.


This article is published as Aidala, C., Y. Akiba, M. Alfred, V. Andrieux, N. Apadula, H. Asano, B. Azmoun et al. "Nonperturbative-transverse-momentum broadening in dihadron angular correlations in s N N= 200 GeV proton-nucleus collisions." Physical Review C 99, no. 4 (2019): 044912. DOI: 10.1103/PhysRevC.99.044912. Posted with permission.