Disentangling Sources of Momentum Fluctuations in and Collisions with the ATLAS Detector
Collaboration
23 pages
Published in:
- Phys.Rev.Lett. 133 (2024) 25, 252301
- Published: Dec 16, 2024
e-Print:
- 2407.06413 [nucl-ex]
DOI:
- 10.1103/PhysRevLett.133.252301 (publication)
Report number:
- CERN-EP-2024-173
Experiments:
Citations per year
Abstract: (APS)
High-energy nuclear collisions create a quark-gluon plasma, whose initial condition and subsequent expansion vary from event to event, impacting the distribution of the eventwise average transverse momentum []. Disentangling the contributions from fluctuations in the nuclear overlap size (geometrical component) and other sources at a fixed size (intrinsic component) remains a challenge. This problem is addressed by measuring the mean, variance, and skewness of in and collisions at and 5.44 TeV, respectively, using the ATLAS detector at the LHC. All observables show distinct features in ultracentral collisions, which are explained by a suppression of the geometrical component as the overlap area reaches its maximum. These results demonstrate a new technique to separate geometrical and intrinsic fluctuations, providing constraints on initial conditions and properties of the quark-gluon plasma, such as the speed of sound.Note:
- All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2021-20/
References(52)
Figures(7)
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