{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/analytical-insights-into-the-interplay-of","title":"Analytical insights into the interplay of momentum, multiplicity and the speed of sound in heavy-ion collisions","arxiv_id":"2405.10401","date":"2024-05-16","proceeding":null,"authors":["Gabriel Soares Rocha","Lorenzo Gavassino","Mayank Singh","Jean-François Paquet"],"abstract":"We introduce a minimal model of ultracentral heavy-ion collisions to study the relation between the speed of sound of the produced plasma and the final particles' energy and multiplicity. We discuss how the particles' multiplicity $N_{\\textrm{tot}}$ and average energy $E_{\\textrm{tot}}/N_{\\textrm{tot}}$ is related to the speed of sound $c_s$ by $c_s^2=d \\ln (E_{\\textrm{tot}}/N_{\\textrm{tot}})/d\\ln N_{\\textrm{tot}}$ if the fluid is inviscid, its speed of sound is constant and all final particles can be measured. We show that finite rapidity cuts on the particles' multiplicity $N$ and energy $E$ introduce corrections between $c_s^2$ and $d \\ln (E/N)/d\\ln N$ that depend on the system's lifetime. We study analytically these deviations with the Gubser hydrodynamic solution, finding that, for ultrarelativistic bosons, they scale as the ratio of the freezeout temperature $T_{\\mathrm{FO}}$ over the maximum initial temperature of the fluid $T_{0}$; the non-thermodynamic aspect of these corrections is highlighted through their dependence on the system's initial conditions.","url_abs":"https://arxiv.org/abs/2405.10401v2","url_pdf":"https://arxiv.org/pdf/2405.10401v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"analytical-insights-into-the-interplay-of","repo_url":"https://github.com/gabriel-sr151/cylindrical-sym-cf","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}