Nobel prize in physics awarded for discovery of high-energy neutrinos
· New Scientist
Francis Halzen at the University of Wisconsin–Madison has won the 2026 Nobel prize in physics for his work on spotting ghostly particles called neutrinos using a detector at the South Pole.
Neutrinos are subatomic particles that rarely interact with material, are electrically neutral and perfuse the whole universe. Because of this, we can detect neutrinos that originated far away in the cosmos, trace their origin and learn more about the nature of the universe. Cosmic neutrinos are produced when a proton collides with another particle.
Visit tr-sport.click for more information.
Read moreGhostly particles might just break our understanding of the universe
If you hold your hand out flat, more than a billion neutrinos will pass through it every second. These originate from the sun, but Halzen’s work concerns the much more rare and high-energy neutrinos coming from deep within the cosmos, and what their detection can tell us about the universe.
Advertisement
if( window?.adverts?.addToArray ) { window.adverts.addToArray( { "pos": "mid-article-slot" } ); }Neutrinos act like “ghost-like messengers from the cosmos”, said Mark Pearce, chair of the Novel committee for physics, at a press conference. “It’s a way of bringing us information about distant cosmic sources which we’re unable to acquire in other ways.”
Halzen proposed in 1988 to use the Antarctic ice as a neutrino detector, then went on to spearhead an international collaboration of more than 450 people from 58 institutions in 14 countries to make the IceCube Neutrino Observatory a reality.
The detector uses thousands of light sensors buried 2 kilometres under the surface of the ice, in deep holes drilled using hot water. As neutrinos shoot through Earth they interact with the ice, creating Cherenkov radiation and emitting blue light. The network of light sensors allows scientists to trace their trajectory back to their origin point, revealing vital information about their formation.
Sign up to Lost in Space-Time Sign up to newsletterHalzen calculated that if you build a neutrino collector 1 cubic kilometre in size, you’d detect one neutrino per day. The experiment was completed in 2011 and the first neutrinos were detected just two years later.
“When I reflect on this moment I have to emphasise how lucky I was,” said Halzen, addressing the press conference by phone. “Because when we started this project, everybody realised this was maybe a good idea, but very few thought it would work – including myself. So this was kind of an adventure where success was not guaranteed and we were lucky to overcome the various challenges. It was a long journey but finally it worked.”
Halzen said that he hopes the prize will reflect on the collaborators who worked on the project in the early days.
The IceCube detector has gone on to make many more discoveries. In 2017 it helped to identify the first definitive source for a single high-energy cosmic neutrino: a blazar called TXS 0506+056, blasting a huge jet of energy towards Earth. In 2023 it identified neutrinos from within our own galaxy, the Milky Way, which are typically overwhelmed by stronger signals from the rest of the universe.
Speaking of winning the award, Halzen said “It was a great surprise and I didn’t expect it. It’s a great pleasure.”
On Time: The physics that makes the universe tick
See Jim Al-Khalili at New Scientist Live 2026
Find out more