A1 Journal article (refereed)
Jet evolution in a dense medium : event-by-event fluctuations and multi-particle correlations (2017)
Escobedo Espinosa, M., & Iancu, E. (2017). Jet evolution in a dense medium : event-by-event fluctuations and multi-particle correlations. Nuclear Physics A, 967, 449-452. https://doi.org/10.1016/j.nuclphysa.2017.05.031
JYU authors or editors
Publication details
All authors or editors: Escobedo Espinosa, Miguel; Iancu, Edmond
Journal or series: Nuclear Physics A
ISSN: 0375-9474
eISSN: 1873-1554
Publication year: 2017
Volume: 967
Issue number: 0
Pages range: 449-452
Publisher: Elsevier BV
Publication country: Netherlands
Publication language: English
DOI: https://doi.org/10.1016/j.nuclphysa.2017.05.031
Publication open access: Other way freely accessible online
Publication channel open access:
Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/55522
Additional information: Special Issue: The 26th International Conference on Ultra-relativistic Nucleus-Nucleus Collisions: Quark Matter 2017. Hyatt Regency Hotel, Chicago, USA, 5–11 February 2017. Edited by Ulrich Heinz, Olga Evdokimov and Peter Jacobs
Abstract
We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations, the jet evolution is a Markovian stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions describing the gluon distribution in the space of energy [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv:arXiv:1601.03629, doi:http://dx.doi.org/10.1007/JHEP05(2016)008, M. A. Escobedo, E. Iancu, Multi-particle correlations and KNO scaling in the medium-induced jet evolution, JHEP 12 (2016) 104. arXiv:arXiv:1609.06104, doi:http://dx.doi.org/10.1007/JHEP12(2016)104]. Using these results, we study the event-by-event distribution of the energy lost by the jet at large angles and of the multiplicities of the soft particles which carry this energy. We find that the event-by-event fluctuations are huge: the standard deviation in the energy loss is parametrically as large as its mean value [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv:arXiv:1601.03629, doi:http://dx.doi.org/10.1007/JHEP05(2016)008]. This has important consequences for the phenomenology of di-jet asymmetry in Pb+Pb collisions at the LHC: it implies that the fluctuations in the branching process can contribute to the measured asymmetry on an equal footing with the geometry of the di-jet event (i.e. as the difference between the in-medium path lengths of the two jets). We compute the higher moments of the multiplicity distribution and identify a remarkable regularity known as Koba-Nielsen-Olesen (KNO) scaling [M. A. Escobedo, E. Iancu, Multi-particle correlations and KNO scaling in the medium-induced jet evolution, JHEP 12 (2016) 104. arXiv:arXiv:1609.06104, doi:http://dx.doi.org/10.1007/JHEP12(2016)104]]. These predictions could be tested via event-by-event measurements of the di-jet asymmetry.
Free keywords: jet evolution; Markovian stochastic process
Contributing organizations
Related projects
- Kvanttiväridynamiikka suurella energia/2
- Lappi, Tuomas
- Research Council of Finland
Ministry reporting: Yes
Reporting Year: 2017
JUFO rating: 1