Abstract
We present STAR measurements of strange hadron (KS0, Λ, Λ, Ξ-, Ξ+, ω-, ω+, and φ) production at midrapidity (|y|<0.5) in Au+Au collisions at sNN = 7.7-39 GeV from the Beam Energy Scan Program at the Relativistic Heavy Ion Collider (RHIC). Transverse-momentum spectra, averaged transverse mass, and the overall integrated yields of these strange hadrons are presented versus the centrality and collision energy. Antibaryon-to-baryon ratios (Λ/Λ, Ξ+/Ξ-, ω+/ω-) are presented as well and used to test a thermal statistical model and to extract the temperature normalized strangeness and baryon chemical potentials at hadronic freeze-out (μB/Tch and μS/Tch) in central collisions. Strange baryon-to-pion ratios are compared to various model predictions in central collisions for all energies. The nuclear modification factors (RCP) and antibaryon-to-meson ratios as a function of transverse momentum are presented for all collision energies. The KS0 RCP shows no suppression for pT up to 3.5 GeV/c at energies of 7.7 and 11.5 GeV. The Λ/KS0 ratio also shows baryon-to-meson enhancement at intermediate pT (≈2.5 GeV/c) in central collisions at energies above 19.6 GeV. Both observations suggest that there is likely a change of the underlying strange quark dynamics at collision energies below 19.6 GeV.
Original language | English |
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Article number | 034909 |
Journal | Physical Review C |
Volume | 102 |
Issue number | 3 |
DOIs | |
State | Published - Sep 2020 |
Bibliographical note
Publisher Copyright:© 2020 American Physical Society.
Funding
We thank the RHIC Operations Group and RCF at BNL, the NERSC Center at LBNL, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science, the U.S. National Science Foundation, the Ministry of Education and Science of the Russian Federation, National Natural Science Foundation of China, Chinese Academy of Science, the Ministry of Science and Technology of China and the Chinese Ministry of Education, the National Research Foundation of Korea, Czech Science Foundation and Ministry of Education, Youth and Sports of the Czech Republic, Hungarian National Research, Development and Innovation Office, New National Excellency Programme of the Hungarian Ministry of Human Capacities, Department of Atomic Energy and Department of Science and Technology of the Government of India, the National Science Centre of Poland, the Ministry of Science, Education and Sports of the Republic of Croatia, RosAtom of Russia, German Bundesministerium fur Bildung, Wissenschaft, Forschung and Technologie (BMBF), and the Helmholtz Association.
Funders | Funder number |
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Department of Atomic Energy and Department of Science and Technology | |
Hungarian Ministry of Human Capacities | |
RosAtom of Russia and German Bundesministerium fur Bildung, Wissenschaft, Forschung and Technologie | |
National Science Foundation Arctic Social Science Program | |
Office of Science Programs | |
Institute for Nuclear Physics | |
National Natural Science Foundation of China (NSFC) | |
Ministerstvo Školství, Mládeže a Tělovýchovy | |
Grantová Agentura České Republiky | |
Ministry of Education of the People's Republic of China | |
Bundesministerium für Bildung und Forschung | |
Chinese Academy of Sciences | |
Ministry of Science and Technology of the People's Republic of China | |
Ministarstvo Obrazovanja, Znanosti i Sporta | |
Ministry for Education and Science of the Russian Federation | |
National Research Foundation of Korea | |
Narodowe Centrum Nauki | |
Max Delbrück Center for Molecular Medicine in the Helmholtz Association | |
Nemzeti Kutatási Fejlesztési és Innovációs Hivatal |
ASJC Scopus subject areas
- Nuclear and High Energy Physics