Abstract
We report measurements of the nuclear modification factor for charged hadrons as well as identified , , and for collision energies of , 11.5, 14.5, 19.6, 27, 39, and 62.4 GeV. We observe a clear high- net suppression in central collisions at 62.4 GeV for charged hadrons which evolves smoothly to a large net enhancement at lower energies. This trend is driven by the evolution of the pion spectra but is also very similar for the kaon spectra. While the magnitude of the proton at high does depend on the collision energy, neither the proton nor the antiproton at high exhibit net suppression at any energy. A study of how the binary collision-scaled high- yield evolves with centrality reveals a nonmonotonic shape that is consistent with the idea that jet quenching is increasing faster than the combined phenomena that lead to enhancement.
- Received 11 July 2017
- Revised 29 March 2018
DOI:https://doi.org/10.1103/PhysRevLett.121.032301
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