Measurements of H Λ3 and H Λ4 Lifetimes and Yields in Au+Au Collisions in the High Baryon Density Region

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We report precision measurements of hypernuclei HΛ3 and HΛ4 lifetimes obtained from Au+Au collisions at sNN=3.0 GeV and 7.2 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider, and the first measurement of HΛ3 and HΛ4 midrapidity yields in Au+Au collisions at sNN=3.0 GeV. HΛ3 and HΛ4, being the two simplest bound states composed of hyperons and nucleons, are cornerstones in the field of hypernuclear physics. Their lifetimes are measured to be 221±15(stat)±19(syst) ps for HΛ3 and 218±6(stat)±13(syst) ps for HΛ4. The pT-integrated yields of HΛ3 and HΛ4 are presented in different centrality and rapidity intervals. It is observed that the shape of the rapidity distribution of HΛ4 is different for 0%-10% and 10%-50% centrality collisions. Thermal model calculations, using the canonical ensemble for strangeness, describes the HΛ3 yield well, while underestimating the HΛ4 yield. Transport models, combining baryonic mean-field and coalescence (jam) or utilizing dynamical cluster formation via baryonic interactions (phqmd) for light nuclei and hypernuclei production, approximately describe the measured HΛ3 and HΛ4 yields. Our measurements provide means to precisely assess our understanding of the fundamental baryonic interactions with strange quarks, which can impact our understanding of more complicated systems involving hyperons, such as the interior of neutron stars or exotic hypernuclei.

Original languageEnglish
Article number202301
JournalPhysical Review Letters
Issue number20
StatePublished - May 20 2022

Bibliographical note

Funding Information:
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, 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 Higher Education Sprout Project by Ministry of Education at NCKU, 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, and German Bundesministerium für Bildung, Wissenschaft, Forschung and Technologie (BMBF), Helmholtz Association, Ministry of Education, Culture, Sports, Science, and Technology (MEXT) and Japan Society for the Promotion of Science (JSPS).

Publisher Copyright:
© 2022 American Physical Society.

ASJC Scopus subject areas

  • Physics and Astronomy (all)


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