First-ever evidence of the antimatter partner of hyperhelium-4
Collisions between heavy ions at the Large Hadron Collider (LHC) create quark-gluon plasma, a state of matter thought to have existed shortly after the Big Bang. These collisions also produce atomic nuclei, exotic hypernuclei, and antimatter counterparts. Studying these forms of matter helps scientists understand hadron formation and the matter-antimatter imbalance in the Universe.
Hypernuclei are rare, exotic nuclei of protons, neutrons, and hyperons (particles with strange quarks). Despite being discovered over 70 years ago in cosmic rays, hypernuclei remain challenging to study in the lab, making them an ongoing focus of interest for physicists.
In heavy-ion collisions, hypernuclei are produced in significant amounts, with the hypertriton (composed of a proton, neutron, and lambda hyperon) and its antimatter counterpart, antihypertriton, being the only ones observed until recently.
Hypertriton contains a lambda hyperon, which holds a strange quark, while antihypertriton consists of an antiproton, an antineutron, and an antilambda.
