Measurements of azimuthal anisotropy and charged-particle multiplicity in + Au collisions at , 62.4, 39, and 19.6 GeV
Here, we present measurements of the elliptic flow ( v 2 ) as a function of transverse momentum ( p T ), pseudorapidity ( η ), and centrality in d + Au collisions at √ s NN = 200 , 62.4, 39, and 19.6 GeV. The beam-energy scan of d + Au collisions provides a testing ground for the onset of flow signatures in small collision systems. We measure a nonzero v 2 signal at all four collision energies, which, at midrapidity and low p T , is consistent with predictions from viscous hydrodynamic models. Comparisons with calculations from parton transport models (based on the ampt Monte Carlo generator) show good agreement with the data at midrapidity to forward ( d -going) rapidities and low p T . At backward (Au-going) rapidities and p T > 1.5 GeV / c , the data diverges from ampt calculations of v 2 relative to the initial geometry, indicating the possible dominance of nongeometry related correlations, referred to as nonflow. We also present measurements of the charged-particle multiplicity ( d N ch / d η ) as a function of η in central d + Au collisions at the same energies. We find that in d + Au collisions at √ s NN = 200 GeV the v 2 scales with d N ch / d η over all η in the PHENIX acceptance. At √ s NN = 62.4 , and 39 GeV, v 2 scales with d N ch / d η at midrapidity and forward rapidity, but falls off at backward rapidity. This is thus a departure from the d N ch / d η scaling may be a further indication of nonflow effects dominating at backward rapidity.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC). Nuclear Physics (NP) (SC-26); USDOE Office of Science (SC), Nuclear Physics (NP); USDOE
- Contributing Organization:
- PHENIX Collaboration
- Grant/Contract Number:
- AC52-06NA25396; SC0012704
- OSTI ID:
- 1416308
- Alternate ID(s):
- OSTI ID: 1412785; OSTI ID: 1414854
- Report Number(s):
- LA-UR-17-27785; BNL-114809-2017-JA; PRVCAN; TRN: US1800912
- Journal Information:
- Physical Review C, Vol. 96, Issue 6; ISSN 2469-9985
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Creation of quark–gluon plasma droplets with three distinct geometries
|
journal | December 2018 |
Influence of electromagnetic fields in proton-nucleus collisions at relativistic energy
|
journal | January 2020 |
Examination of Flow and Non-Flow Factorization Methods in Small Collision Systems | text | January 2019 |
Similar Records
Measurement of emission-angle anisotropy via long-range angular correlations with high- hadrons in and collisions at GeV
Scaling properties of fractional momentum loss of high- hadrons in nucleus-nucleus collisions at from 62.4 GeV to 2.76 TeV