Seven ‘ghost particles’ caught by IceCube at South Pole

Researchers at the IceCube Observatory, buried beneath the Antarctic ice, have identified seven potential instances of elusive “ghost particles” or astrophysical tau neutrinos as they journeyed through Earth. These neutrinos are pivotal for understanding the cosmic exchanges between Earth and the vast universe.

Astrophysical tau neutrinos are a type of neutrino, a particle that is virtually undetectable as it carries no mass or electric charge, allowing it to traverse the cosmos at light speed without interaction. An astounding number, approximately 100 trillion of these neutrinos, flow through our bodies every second, earning them the nickname “ghost particles.”

Originating from cosmic events at the fringes of the Milky Way, astrophysical neutrinos come in three varieties: electron neutrinos, muon neutrinos, and the rare tau neutrinos. IceCube’s mission is to capture these elusive particles, having first discovered astrophysical neutrinos in 2013.

“The presence of seven tau neutrino event candidates, along with a significantly low background noise, strongly suggests the improbability of these being false signals,” explained Doug Cowen, a Penn State University physics professor and co-leader of the study.

This finding not only supports IceCube’s initial detection of astrophysical neutrinos but also hints at the observatory’s capability to make groundbreaking discoveries. IceCube detects these neutrinos using digital optical modules (DOMs), spheres equipped with sensors, submerged in Antarctic ice. The observatory’s 5,160 DOMs lie in wait for neutrinos to interact with ice molecules, producing detectable charged particles.

Understanding the oscillation patterns of neutrinos could unveil the origins and the cosmic events propelling these ghost particles across space. “This discovery opens up the exciting possibility of using tau neutrinos to explore new physics,” Cowen remarked.