Becky Ferreira, 13 December 2022, Motherboard (Vice Media)

Excerpt:

>One possible method to search for dark matter is to capture “antinuclei,” which are the antimatter versions of the nuclei found in normal atoms. Antinuclei might be generated by interactions between dark matter particles, distinguishing them as a potential window into the longstanding question the nature of this elusive material.

>However, most antinuclei are forged in the dense messy region near the center of our galaxy, tens of thousands of light years away from Earth, so it’s not clear how many of these messengers can reach us across that vast distance.

>Now, scientists have used the ALICE detector at the Large Hadron Collider, the biggest particle accelerator on Earth, to estimate the “transparency” of our galaxy to helium antinuclei, a measurement that makes it possible to estimate how far these particles can travel before they encounter regular matter and disappear.

> 

>The results revealed that antinuclei may indeed voyage across the Milky Way to reach Earth, making them “a very promising channel for the discovery of dark matter” now that we know we can likely detect them here, according to a study published on Monday [Dec. 12] in Nature Physics.

>“Antinuclei don’t travel straight through the galaxy because they are charged and there are magnetic fields” in the Milky Way, said Maximiliano Puccio, a member of the ALICE collaboration and a co-author of the new study, in a call with Motherboard.

>“This means they have a very contorted path of coming to the Earth that is much longer than the linear distance from the center of the galaxy.”

>“When we put all the ingredients together” at CERN “and we saw that half of the [antinuclei] survive, that was quite something,” he added, noting that the finding suggests that these strange particles can wind up around Earth.

Nature Physics, 2022. DOI 10.1038/s41567-022-01804-8