New hypernuclei measurements from STAR

¹ OSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
² Institute of Particle Physics and Key Laboratory of Quark & Lepton Physics (MOE), Central China Normal University, 430079, Wuhan, China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 17 April 2026

Abstract

Hypernuclei are bound states of hyperons (Y) and nucleons (N). Measurements on their yields can help us investigate their production mechanisms. In particular, the _Λ⁵He and _Λ⁴H(e) are substantially tighter bound compared to the _Λ³He. The large radius of the _Λ³He leads to suppression in coalescence models, but not in the thermal model where the size of the nucleus does not play a role. As such, studying the A = 3–5 hypernuclei yields allow us to extract information on the effects of hypernuclear binding on hypernuclei production in heavy-ion collisions.

In these proceedings, we present measurements of _Λ⁵He yields in Au+Au collisions at √s_NN = 3.0 GeV, _Λ⁴H(e) yields in Au+Au collisions at √s_NN = 3.0−4.5 GeV, and _Λ³H yields in Au+Au collisions at √s_NN = 3−27 GeV. Results on the directed flow of hypernuclei are also reported. The physics implications of these measurements are discussed.