A1 Journal article (refereed)
Enhanced Deuteron Coalescence Probability in Jets (2023)

ALICE Collaboration. (2023). Enhanced Deuteron Coalescence Probability in Jets. Physical Review Letters, 131, Article 042301. https://doi.org/10.1103/PhysRevLett.131.042301

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Publication details

All authors or editors: ALICE Collaboration

Journal or series: Physical Review Letters

ISSN: 0031-9007

eISSN: 1079-7114

Publication year: 2023

Publication date: 26/07/2023

Volume: 131

Article number: 042301

Publisher: American Physical Society (APS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevLett.131.042301

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/88939

Web address of parallel published publication (pre-print): https://arxiv.org/abs/2211.15204

Abstract

The transverse-momentum (pT) spectra and coalescence parameters B2 of (anti)deuterons are measured in p-p collisions at √s=13  TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest pT in the event (pT lead > 5 GeV /c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using PYTHIA8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in PYTHIA8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B2Jet is not reproduced by the models, which instead give a decreasing trend.

Keywords: particle physics

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Ministry reporting: Yes

Reporting Year: 2023

JUFO rating: 3