English

Investigating Sources of Angular Correlations at High pT in Nucleon-Nucleon and Nucleus-Nucleus Collisions at the CERN SPS

Nuclear Experiment 2019-08-14 v2

Abstract

Angular correlations of high-pT hadrons can serve as a probe of interactions of partons with the dense medium produced in high-energy heavy-ion collisions but other effects may also be important at SPS energies. To study the various contributions, NA49 has performed an energy and system-size scan of two-particle azimuthal correlations in Pb+Pb, Si+Si and p+p collisions at sqrt(sNN) = 17.3 GeV, as well as central Pb+Pb collisions at 6.3, 7.6, 8.8 and 12.3 GeV. These results were compared to UrQMD simulations. NA49 results show a flattened away side of C2(dphi) in central Pb+Pb (Au+Au) collisions which depends weakly on collision energy even for low SPS energies. This is at odds with the standard scenario of parton energy loss. On the other hand, the near-side peak amplitude drops visibly with decreasing collision energy, turning into a depletion below sqrt(sNN) = 8.8 GeV. UrQMD describes the correlation functions on the away side but disagrees on the near side.

Keywords

Cite

@article{arxiv.0907.4403,
  title  = {Investigating Sources of Angular Correlations at High pT in Nucleon-Nucleon and Nucleus-Nucleus Collisions at the CERN SPS},
  author = {Marek Szuba},
  journal= {arXiv preprint arXiv:0907.4403},
  year   = {2019}
}

Comments

4 pages, 4 figures. To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee