Strange 'hypernuclei' detected at the Large Hadron Collider
The European Council for Nuclear Research (CERN) has reported that the Large Hadron Collider (LHC) has detected a strange and rare kind of atomic nucleus called "hypertriton."
As per the official release, the researchers from the LHCb experiment presented their findings at the EPS-HEP conference in 2023. At the conference, they explained how they used a novel technique to pore over old data collected between 2016 and 2018 to "observe" the rare hypernuclei, "hypertriton," and "antihypertriton."
A surprising find
Over the two years, LHCb physicists recorded over 100 of these rare and unstable hypernuclei. Forms of atomic cores, hypernuclei, contain a unique "flavor" of quark (a type of elementary particle that forms all mass) in one of their nuclear building blocks. This discovery could potentially aid our understanding of the mysterious "antihelium" that has been tentatively detected in the vast expanse of the cosmos.
By smashing particles at high speed in the LHC, physicists can pick through the nucleic debris field, so to speak, to see what they can see—especially short-lived things like hypernuclei. When experiments are run, not only are the major building blocks uncovered (like baryons - protons and neutrons), but also their constituent parts called quarks.
On average, these quarks are dominated by just three flavors: two up quarks and one down quark for protons, and one up quark and two down quarks for neutrons. However, "hypernuclei" are less common and contain something called a "hyperon" and the expected neutrons and protons. They, in turn, have their own "strange" quarks not seen in other baryons.
"Hypertriton" is one such "hypernuclei" that comes with a special baryon called a "Lambda hyperon." This isn't just interesting for particle physics' sake, but many physicists believe "hyperons" are created within neutron stars, remnants of massive stars that have undergone supernova.
The density of these celestial bodies makes it challenging for scientists to investigate the physics involved, so any data that can be gleaned is priceless. However, "hyperons" decay rapidly, making it necessary to search for "hypertritons" and their antiparticles in a particle collider, as it is the most viable option.
To this end, LHCb used a new technique to find "hypertriton" and "antihypertriton" by detecting their decay products from data collected during a previous collider run, namely "pions" and helium/antihelium nuclei. By measuring the masses of the nuclei, they found that the decay of "hypertritons" and "antihypertritons" could be their only likely source.
The implications for astrophysics are thrilling. Physicists can better understand the amount of antihelium that could potentially reach Earth by measuring how it is created and destroyed in space. For example, this information could either support or refute the previous detection of "antihelium" in 2018.

A revolutionary technique
This discovery is an exciting and new approach to exploring the characteristics of hypertritons and could have wider implications for subatomic particle research too. It could, for example, potentially help us unlock the secrets as to how the "quarks" in "baryons" are bound together! But let's not get too ahead of ourselves here.
The findings were presented at the European Physical Society Conference on High Energy Physics and will, Science Alert reports, be published soon.