Modification of jet substructure in heavy ion collisions as a probe of the resolution length of quark-gluon plasma
| Autor: | Daniel Pablos, Guilherme Milhano, Jorge Casalderrey-Solana, Krishna Rajagopal |
|---|---|
| Přispěvatelé: | Universitat de Barcelona |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Nuclear and High Energy Physics
Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Plasma (Gasos ionitzats) Wake 01 natural sciences Nuclear physics High Energy Physics - Phenomenology (hep-ph) Jets (Astrofísica) 0103 physical sciences lcsh:Nuclear and particle physics. Atomic energy. Radioactivity 010306 general physics Physics Plasma (Ionized gases) Heavy ion collision 010308 nuclear & particles physics Drop (liquid) Col·lisions d'ions pesats Observable Plasma Heavy Ion Phenomenology Astrophysical jets High Energy Physics - Phenomenology Phase space Quark–gluon plasma Substructure lcsh:QC770-798 Heavy ion High Energy Physics::Experiment |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação instacron:RCAAP Journal of High Energy Physics, Vol 2020, Iss 1, Pp 1-54 (2020) Recercat. Dipósit de la Recerca de Catalunya instname Journal of High Energy Physics (JHEP) Dipòsit Digital de la UB Universidad de Barcelona Journal of High Energy Physics |
| Popis: | We present an analysis of the role that the quark-gluon plasma (QGP) resolution length, the minimal distance by which two nearby colored charges in a jet must be separated such that they engage with the plasma independently, plays in understanding the modification of jet substructure due to interaction with QGP. We identify a set of observables that are sensitive to whether jets are quenched as if they are single energetic colored objects or whether the medium that quenches them has the ability to resolve the internal structure of the jet. Using the hybrid strong/weak coupling model, we find that although the ungroomed jet mass is not suitable for this purpose (because it is more sensitive to effects coming from particles reconstructed as a part of a jet that originate from the wake that the jet leaves in the plasma), groomed observables such as the number of Soft Drop splittings $n_{\rm SD}$, the momentum sharing fraction $z_g$, or the groomed jet mass are particularly well-suited to discriminate the degree to which the QGP medium resolves substructure within a jet. In order to find the optimal grooming strategy, we explore different cuts in the Lund plane that allow for a clear identification of the regions of Soft Drop phase space that enhance the differences in the jet substructure between jets in vacuum and quenched jets. Comparison with present data seems to disfavor an "infinite resolution length", which is to say the hypothesis that the medium interacts with the jet as if it were a single energetic colored object. Our analysis indicates that as the precision of experimental measurements of jet substructure observables and the control over uncertainties in their calculation improves, it will become possible to constrain the value of the resolution length of QGP, in addition to seeing how the substructure of jets is modified via their passage through it. 50 pages, 5 figures |
| Databáze: | OpenAIRE |
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