TY  - INPR
T1  - Observation of the antimatter hypernucleus ⁴¯ΛH
T2  - arXiv
N2  - Matter-antimatter asymmetry is a research topic of fundamental interest, as it is the basis for the existence of the matter world, which survived annihilation with antimatter in the early Universe. 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 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  - 2023
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/86191
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-861918
UR  - https://arxiv.org/abs/2310.12674v1
IS  - 2310.12674v1
PB  - arXiv
ER  -