Observation of the antimatter hypernucleus ¯Λ4¯H

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F24%3A00603090" target="_blank" >RIV/61389005:_____/24:00603090 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1038/s41586-024-07823-0" target="_blank" >https://doi.org/10.1038/s41586-024-07823-0</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s41586-024-07823-0" target="_blank" >10.1038/s41586-024-07823-0</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Observation of the antimatter hypernucleus ¯Λ4¯H

Popis výsledku v původním jazyce

At the origin of the Universe, an asymmetry between the amount of created matter and antimatter led to the matter-dominated Universe as we know it today. The origins of this asymmetry remain unknown so far. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter1–6. Much of the created antimatter escapes the rapidly expanding fireball without annihilating, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and to study their properties7–14, hoping to shed some light on the existing questions on the asymmetry between matter and antimatter. Here we report the observation of the antimatter hypernucleus H¯Λ¯4, composed of a 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 Collider15,16. In total, 15.6 candidate H¯Λ¯4 antimatter hypernuclei are obtained with an estimated background count of 6.4. The lifetimes of the antihypernuclei H¯Λ¯3 and H¯Λ¯4 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 (hypernuclei and/or antihypernuclei) and (anti)nuclei (nuclei and/or antinuclei) are also measured and compared with theoretical model predictions, shedding light on their production mechanisms.

Název v anglickém jazyce

Observation of the antimatter hypernucleus ¯Λ4¯H

Popis výsledku anglicky

At the origin of the Universe, an asymmetry between the amount of created matter and antimatter led to the matter-dominated Universe as we know it today. The origins of this asymmetry remain unknown so far. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter1–6. Much of the created antimatter escapes the rapidly expanding fireball without annihilating, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and to study their properties7–14, hoping to shed some light on the existing questions on the asymmetry between matter and antimatter. Here we report the observation of the antimatter hypernucleus H¯Λ¯4, composed of a 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 Collider15,16. In total, 15.6 candidate H¯Λ¯4 antimatter hypernuclei are obtained with an estimated background count of 6.4. The lifetimes of the antihypernuclei H¯Λ¯3 and H¯Λ¯4 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 (hypernuclei and/or antihypernuclei) and (anti)nuclei (nuclei and/or antinuclei) are also measured and compared with theoretical model predictions, shedding light on their production mechanisms.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Nature

ISSN

0028-0836

e-ISSN

1476-4687

Svazek periodika

632

Číslo periodika v rámci svazku

8027

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

6

Strana od-do

1026-1031

Kód UT WoS článku

001373611600001

EID výsledku v databázi Scopus

2-s2.0-85202579268