Centrality dependence of proton and light nuclei yields as a consequence of baryon annihilation in the hadronic phase
- The centrality dependence of the p/π ratio measured by the ALICE Collaboration in 5.02 TeV Pb-Pb collisions indicates a statistically significant suppression with the increase of the charged particle multiplicity once the centrality-correlated part of the systematic uncertainty is eliminated from the data. We argue that this behavior can be attributed to baryon annihilation in the hadronic phase. By implementing the BB¯↔5π reaction within a generalized partial chemical equilibrium framework, we estimate the annihilation freeze-out temperature at different centralities, which decreases with increasing charged particle multiplicity and yields Tann=132±5 MeV in 0-5% most central collisions. This value is considerably below the hadronization temperature of Thad∼160 MeV but above the thermal (kinetic) freeze-out temperature of Tkin∼100 MeV. Baryon annihilation reactions thus remain relevant in the initial stage of the hadronic phase but freeze out before (pseudo-)elastic hadronic scatterings. One experimentally testable consequence of this picture is a suppression of various light nuclei to proton ratios in central collisions of heavy ions.
Author: | Volodymyr VovchenkoORCiDGND, Volker KochORCiD |
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URN: | urn:nbn:de:hebis:30:3-784035 |
DOI: | https://doi.org/10.1016/j.physletb.2022.137577 |
ISSN: | 0370-2693 |
Parent Title (English): | Physics Letters B |
Publisher: | Elsevier |
Place of publication: | Amsterdam |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2022/11/21 |
Date of first Publication: | 2022/11/18 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2023/10/09 |
Volume: | 835 |
Issue: | 137577 |
Page Number: | 6 |
HeBIS-PPN: | 513581375 |
Institutes: | Physik |
Wissenschaftliche Zentren und koordinierte Programme / Frankfurt Institute for Advanced Studies (FIAS) | |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Sammlungen: | Universitätspublikationen |
Licence (German): | Creative Commons - CC BY - Namensnennung 4.0 International |