English

Event-by-event hydrodynamics $+$ jet energy loss: A solution to the $R_{AA} \otimes v_2$ puzzle

Nuclear Theory 2016-06-29 v2 High Energy Physics - Phenomenology Nuclear Experiment

Abstract

High pT>10p_T > 10 GeV elliptic flow, which is experimentally measured via the correlation between soft and hard hadrons, receives competing contributions from event-by-event fluctuations of the low pTp_T elliptic flow and event plane angle fluctuations in the soft sector. In this paper, a proper account of these event-by-event fluctuations in the soft sector, modeled via viscous hydrodynamics, is combined with a jet energy loss model to reveal that the positive contribution from low pTp_T v2v_2 fluctuations overwhelms the negative contributions from event plane fluctuations. This leads to an enhancement of high pT>10p_T > 10 GeV elliptic flow in comparison to previous calculations and provides a natural solution to the decade long high pTp_T RAAv2R_{AA} \otimes v_2 puzzle. We also present the first theoretical calculation of high pTp_T v3v_3, which is shown to be compatible with current LHC data. Furthermore, we discuss how short wavelength jet-medium physics can be deconvoluted from the physics of soft, bulk event-by-event flow observables using event shape engineering techniques.

Keywords

Cite

@article{arxiv.1602.03788,
  title  = {Event-by-event hydrodynamics $+$ jet energy loss: A solution to the $R_{AA} \otimes v_2$ puzzle},
  author = {Jacquelyn Noronha-Hostler and Barbara Betz and Jorge Noronha and Miklos Gyulassy},
  journal= {arXiv preprint arXiv:1602.03788},
  year   = {2016}
}

Comments

7 pages, 3 figures, references added, substantially revised, accepted for publication in Phys. Rev. Lett