Measurements of ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$ Lifetimes and Yields in Au+Au Collisions in the High Baryon Density Region

Abstract

We report precision measurements of hypernuclei ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$ lifetimes obtained from Au+Au collisions at \snn = 3.0\,GeV and 7.2\,GeV collected by the STAR experiment at RHIC, and the first measurement of ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$ mid-rapidity yields in Au+Au collisions at \snn = 3.0\,GeV. ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$, 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 $221\pm 15(stat.)\pm 19(syst.)$\,ps for ${}_{\Lambda }^3\mathrm{H}$ and $218\pm 6(stat.)\pm 13(syst.)$\,ps for ${}_{\Lambda }^4\mathrm{H}$. The $p_T$-integrated yields of ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$ are presented in different centrality and rapidity intervals. It is observed that the shape of the rapidity distribution of ${}_{\Lambda }^4\mathrm{H}$ is different for 0--10\% and 10--50\% centrality collisions. Thermal model calculations, using the canonical ensemble for strangeness, describes the ${}_{\Lambda }^3\mathrm{H}$ yield well, while underestimating the ${}_{\Lambda }^4\mathrm{H}$ 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 ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$ 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.

8 pages, 4 captioned figures

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Cited by in corpus (24)

• The ALICE experiment: a journey through QCD
• Properties of the QCD Matter -- An Experimental Review of Selected Results from RHIC BES Program
• Measurement of the lifetime and $\Lambda$ separation energy of ${}_{\Lambda }^3\mathrm{H}$
• Observation of Directed Flow of Hypernuclei ${}_{\Lambda }^3$H and ${}_{\Lambda }^4$H in $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV Au+Au Collisions at RHIC
• Energy dependence of light hypernuclei production in heavy-ion collisions from a coalescence and statistical-thermal model perspective
• Observation of the Antimatter Hypernucleus ${}_{\bar{\Lambda }}^4\overline{H}$
• Measurement of ${}_{\mathrm{\Lambda }}^4\mathrm{H}$ and ${}_{\mathrm{\Lambda }}^4\mathrm{He}$ binding energy in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV
• Nucleosynthesis of light nuclei and hypernuclei in central Au+Au collisions at $\sqrt{s_{NN}}$=3 GeV
• Midrapidity cluster formation in heavy-ion collisions
• First measurement of A = 4 (anti)hypernuclei at the LHC
• Binding energy of ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\Lambda }^4\mathrm{H}$ via image analyses of nuclear emulsions using deep-learning
• Measurement of ${}_{\Lambda }^3\mathrm{H}$ production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Letter of Intent: the NA60+ experiment
• Hypertriton lifetime
• Precise lifetime measurement of ${}_{\Lambda }^4$H hypernucleus using in-flight ${}^4$He$(K^{-},{\pi }^0{)}_{\Lambda }^4$H reaction
• Hypertriton Production in Au+Au Collisions from STAR BES-II
• Production characteristics of light nuclei, hypertritons and $\Omega$-hypernuclei in Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV
• Production of nuclei and hypernuclei in pion-induced reactions near threshold energies
• Lifetime of the hypertriton
• Probing of EoS with clusters and hypernuclei
• Measurements on the production and properties of light hypernuclei at STAR
• A Data-Guided Coalescence Model for Light Nuclei and Hypernuclei Production in Relativistic Heavy-Ion Collisions at $\sqrt{s_{\mathrm{NN}}}=3$--200 GeV
• Toward a Unified Understanding of the Dense Matter Equation of State
• Nucleation of baryons in relativistic hadron-nucleus collisions