English

DREENA-B framework: first predictions of $R_{AA}$ and $v_2$ within dynamical energy loss formalism in evolving QCD medium

Nuclear Theory 2019-03-12 v2 High Energy Physics - Phenomenology

Abstract

Dynamical energy loss formalism allows generating state-of-the-art suppression predictions in finite size QCD medium, employing a sophisticated model of high-pp_\perp parton interactions with QGP. We here report a major step of introducing medium evolution in the formalism though 1+1D1+1D Bjorken (``B'') expansion, while preserving all complex features of the original dynamical energy loss framework. We use this framework to provide joint RAAR_{AA} and v2v_2 predictions, for the first time within the dynamical energy loss formalism in evolving QCD medium. The predictions are generated for a wide range of observables, i.e. for all types of probes (both light and heavy) and for all centrality regions in both Pb+PbPb+Pb and Xe+XeXe+Xe collisions at the LHC. Where experimental data are available, DREENA-B framework leads to a good joint agreement with v2v_2 and RAAR_{AA} data. Such agreement is encouraging, i.e. may lead us closer to resolving v2v_2 puzzle (difficulty of previous models to jointly explain RAAR_{AA} and v2v_2 data), though this still remains to be thoroughly tested by including state-of-the-art medium evolution within DREENA framework. While introducing medium evolution significantly changes v2v_2 predictions, RAAR_{AA} predictions remain robust and moreover in a good agreement with the experimental data; RAAR_{AA} observable is therefore suitable for calibrating parton-medium interaction model, independently from the medium evolution. Finally, for heavy flavor, we observe a strikingly similar signature of the dead-cone effect on both RAAR_{AA} and v2v_2 - we also provide a simple analytical understanding behind this result. Overall, the results presented here indicate that DREENA framework is a reliable tool for QGP tomography.

Keywords

Cite

@article{arxiv.1805.04786,
  title  = {DREENA-B framework: first predictions of $R_{AA}$ and $v_2$ within dynamical energy loss formalism in evolving QCD medium},
  author = {Dusan Zigic and Igor Salom and Jussi Auvinen and Marko Djordjevic and Magdalena Djordjevic},
  journal= {arXiv preprint arXiv:1805.04786},
  year   = {2019}
}

Comments

14 pages, 2 figures