A machine learning study to identify spinodal clumping in high energy nuclear collisions

  • The coordinate and momentum space configurations of the net baryon number in heavy ion collisions that undergo spinodal decomposition, due to a first-order phase transition, are investigated using state-of-the-art machine-learning methods. Coordinate space clumping, which appears in the spinodal decomposition, leaves strong characteristic imprints on the spatial net density distribution in nearly every event which can be detected by modern machine learning techniques. On the other hand, the corresponding features in the momentum distributions cannot clearly be detected, by the same machine learning methods, in individual events. Only a small subset of events can be systematically differ- entiated if only the momentum space information is available. This is due to the strong similarity of the two event classes, with and without spinodal decomposition. In such sce- narios, conventional event-averaged observables like the baryon number cumulants signal a spinodal non-equilibrium phase transition. Indeed the third-order cumulant, the skewness, does exhibit a peak at the beam energy (Elab = 3–4 A GeV), where the transient hot and dense system created in the heavy ion collision reaches the first-order phase transition.

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Author:Jan SteinheimerORCiDGND, Long-Gang PangORCiD, Kai ZhouORCiD, Volker KochORCiD, Jørgen RandrupORCiD, Horst StöckerORCiDGND
Parent Title (English):Journal of high energy physics
Place of publication:Berlin ; Heidelberg
Document Type:Article
Date of Publication (online):2019/12/16
Date of first Publication:2019/12/16
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2022/10/10
Tag:Heavy Ion Phenomenology; QCD Phenomenology
Page Number:26
Institutes:Physik / Physik
Wissenschaftliche Zentren und koordinierte Programme / Frankfurt Institute for Advanced Studies (FIAS)
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
Licence (German):License LogoCreative Commons - Namensnennung 4.0