TY  - INPR
T1  - Observation of the antimatter hypernucleus ⁴¯ΛH
T2  - arXiv
N2  - Antimatter is a research topic of fundamental interest. Sufficient matter-antimatter asymmetry in the early Universe created the matter-dominated world today. The origin of this asymmetry is not completely understood to date. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the antimatter created escapes the rapidly expanding fireball without annihilation, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties. In this paper, we report the first observation of the antimatter hypernucleus 4Λ¯H¯¯¯¯, composed of an Λ¯, an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy-ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate 4Λ¯H¯¯¯¯ antimatter hypernuclei are obtained with an estimated background count of 6.4. Lifetimes of the antihypernuclei 3Λ¯H¯¯¯¯ and 4Λ¯H¯¯¯¯ are measured and compared with the lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanism.
Y1  - 2024
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/86193
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-861937
UR  - https://arxiv.org/abs/2310.12674v2
IS  - 2310.12674v2
PB  - arXiv
ER  -