Evidence of partonic collectivity in OO collisions through the measurement of $ϕ$, K$^0_{\rm S}$, and $Λ$ elliptic flow
Year: 2026
Type: preprint
Abstract: The first measurement of the elliptic-flow coefficient ($v_{2}$) of $ϕ$, K$^0_{\rm S}$, and $Λ(\overlineΛ)$ hadrons performed in OO collisions at $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV with the ALICE detector is presented as a function of transverse momentum ($p_{\rm T}$) in central and semi-central collisions. For the $ϕ$ meson, in particular, this is the first measurement of the elliptic flow in a small collision system. At low $p_{\rm T}$, a characteristic mass ordering of $v_{2}$ is observed, consistent with collective expansion of the system, in which heavier hadrons are shifted to higher $p_{\rm T}$ by a common velocity field. At intermediate $p_{\rm T}$, above 3 GeV/$c$, a baryon$-$meson splitting with a $10σ$ significance emerges, with the $Λ(\overlineΛ)$ baryon exhibiting larger $v_{2}$ values than mesons, while, despite its mass being close to the mass of the $Λ$, the $ϕ$ follows the K$^{0}_{\rm S}$. The $ϕ$ meson behavior disfavors a purely mass-driven interpretation of the observed patterns and supports the role of hadronization via quark recombination from a collectively flowing partonic medium. These results provide complementary evidence that key signatures of partonic collectivity observed in Pb$-$Pb collisions persist in light nucleus$-$nucleus systems.
Source: arXiv (Cornell University)
Author: ALICE Collaboration
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Villum Fonden, CERN, Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu, Badan Riset dan Inovasi Nasional, European Commission, National Research Foundation, Department of Science and Technology, Ministry of Science and Technology, India, Council of Scientific and Industrial Research, India, University Grants Commission, Deutsche Forschungsgemeinschaft, Ministry of Education, Culture, Sports, Science and Technology, Danmarks Grundforskningsfond, Fundação de Amparo à Pesquisa do Estado de São Paulo, National Natural Science Foundation of China, Österreichischen Akademie der Wissenschaften, Ministry of Education of the People's Republic of China, Austrian Science Fund, Consejo Nacional de Ciencia y Tecnología, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Korea Institute of Science and Technology Information, National Research Foundation of Korea, National Science and Technology Development Agency, Suranaree University of Technology, Vetenskapsrådet, Hrvatska Zaklada za Znanost, Centre National de la Recherche Scientifique, Financiadora de Estudos e Projetos, Danmarks Frie Forskningsfond, Norges Forskningsråd, Forskningsrådet om Hälsa, Arbetsliv och Välfärd, State Committee of Science, Fondo de Cooperación Internacional en Ciencia y Tecnología, Pontificia Universidad Católica del Perú, Istituto Nazionale di Fisica Nucleare, Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, Science and Technology Facilities Council, Japan Society for the Promotion of Science, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, European Regional Development Fund, GSI Helmholtzzentrum für Schwerionenforschung, Institut National de Physique Nucléaire et de Physique des Particules, National Research, Development and Innovation Office, Nuclear Physics
OpenAlex ID: W7224091178