Nobel physics prize goes to IceCube neutrino researcher Francis Halzen
Version 3: New reports add detail rather than alter the outcome: Chiba University researchers held a press conference and welcomed the award, an explainer sets out why the observatory is at the South Pole, and technical coverage says Halzen proposed using Antarctic ice for detection in 1988 and that 28 high-energy neutrinos had been detected by 2013.
In short
Sweden's Royal Swedish Academy of Sciences said on 6 October that the 2026 Nobel Prize in Physics goes to Francis Halzen of the University of Wisconsin-Madison for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy astrophysical neutrinos. IceCube is an international project at the South Pole in which a team from Chiba University takes part. The prize money is 12 million Swedish kronor and the ceremony is set for Stockholm on 10 December.
Read the full story 2 min read
Sweden's Royal Swedish Academy of Sciences announced on 6 October that the 2026 Nobel Prize in Physics will be awarded to Francis Halzen of the University of Wisconsin-Madison, Japanese outlets reported. Sankei, Mainichi and Nikkei xTECH give the citation as decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin. Nippon TV News says Halzen led the research, and TBS News DIG describes him as Belgian-born. [ 1 , 3 , 4 , 5 , 12 , 16 ]
IceCube is a particle observatory near the South Pole. Nippon TV News says 14 countries, 58 institutions and more than 450 people take part, and that holes about 1,500 to 2,500 metres deep in the ice hold 5,160 photodetectors that capture light produced when neutrinos passing under the glacier react with water molecules. Sankei describes a huge underground facility with more than 5,000 detectors at the same depths, and Mainichi says high-sensitivity detectors are set in ice more than one kilometre thick. Asahi Shimbun says neutrinos carry no electric charge and rarely react with other matter, which lets them be used to observe through gas and celestial bodies. [ 3 , 4 , 5 , 19 ]
The documents differ on the project's milestones. Mainichi says construction began in 2005, IceCube was fully operating in 2011, it first detected high-energy neutrinos in 2012 and in 2017 identified the celestial source of the particles. Sankei says the team captured a neutrino from space on 23 September 2017 Japan time. Nippon TV News says the project achieved the world's first observation of cosmic neutrinos from outside the solar system without giving a year. Nikkei xTECH says Halzen proposed using Antarctic ice as a detection medium in 1988, completed the large device around 2011 and had detected 28 high-energy neutrinos by 2013. Asahi says the successful observation of ultra-high-energy neutrinos was announced in 2013, and that neutrinos thought to come from black holes were later observed. [ 3 , 4 , 5 , 16 , 19 ]
Nippon TV News, Sankei and Mainichi say a team from Chiba University takes part in IceCube; Nippon TV names the university's Hadron Cosmic International Research Centre. Nikkei reports that researchers including centre director Shigeru Yoshida held a press conference in Chiba on 6 October. Jiji Press reports Chiba University professors saying they were very happy, and Sankei reports the university contributed through detectors and analysis. Yomiuri carries a comment from Hiroshima University professor Taiji Fukazawa, who works on high-energy cosmic observation, saying IceCube's observation of high-energy neutrinos has revealed a world electromagnetic waves could hardly show and is a strong means of probing where in the universe the highest-energy cosmic rays are accelerated. [ 2 , 3 , 4 , 5 , 11 , 13 , 15 ]
Sankei and Mainichi report the prize money as 12 million Swedish kronor, about 190 million yen. Nippon TV News, Sankei and Mainichi say the ceremony will be held in December in Stockholm, with Sankei and Mainichi specifying 10 December. Mainichi gives Halzen's age as 82. [ 3 , 4 , 5 ]
Why it matters
Several Japanese outlets note that a Chiba University team is part of the IceCube project, tying Japan to a large international physics experiment. The documents say the observation of high-energy cosmic neutrinos is expected to help explain the mechanisms behind the origins of the universe, but give no further consequences.
Key facts
- The 2026 Nobel Prize in Physics was awarded to Francis Halzen of the University of Wisconsin-Madison. [ 1 , 2 , 3 , 4 , 5 , 12 , 16 , 17 ]
- The citation covers decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin. [ 4 , 5 , 16 ]
- IceCube is an international project at the South Pole, and Japanese outlets say a team from Chiba University takes part. [ 3 , 4 , 5 ]
- Nippon TV News says the project involves more than 450 people from 58 institutions in 14 countries, and that 5,160 photodetectors are buried in ice at depths of about 1,500 to 2,500 metres. [ 3 ]
- Sankei and Mainichi say the prize money is 12 million Swedish kronor, about 190 million yen, and the ceremony is set for 10 December in Stockholm. [ 4 , 5 ]
- Mainichi says Halzen is 82 and that IceCube began construction in 2005 and was fully operating in 2011. [ 5 ]
- Nikkei xTECH says Halzen proposed using Antarctic ice as a neutrino detection medium in 1988 and that 28 high-energy neutrinos had been detected by 2013. [ 16 ]
- Nikkei reports Chiba University researchers held a press conference in Chiba on 6 October, and Jiji Press reports professors there said they were very happy. [ 11 , 13 ]
Confirmed by several sources
- The 2026 Nobel Prize in Physics was awarded to Francis Halzen of the University of Wisconsin-Madison. [ 2 , 3 , 4 , 5 , 12 , 16 , 17 ]
- The citation covers decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin. [ 4 , 5 , 16 ]
- IceCube is an international project at the South Pole, and a team from Chiba University takes part. [ 3 , 4 , 5 , 11 ]
- The award ceremony is scheduled for December in Stockholm; Sankei and Mainichi specify 10 December. [ 3 , 4 , 5 ]
- The prize money is 12 million Swedish kronor, about 190 million yen. [ 4 , 5 ]
Still unclear
- Naming of the observatory differs: Sankei, Nippon TV News and others describe it as a neutrino observatory, while Mainichi calls it a “neutron observatory”. Single outlet uses different wording from the others; the documents do not reconcile the difference.
- Dates for the project's detections vary: Mainichi says IceCube first detected high-energy neutrinos in 2012 and identified their source in 2017; Sankei says the team captured a neutrino from space on 23 September 2017 Japan time; Nippon TV News gives no year; Asahi says the observation was announced in 2013; Nikkei xTECH says 28 high-energy neutrinos had been detected by 2013. The documents describe several milestones with different dates and do not present a single common timeline.
- The statement that Halzen proposed using Antarctic ice as a detection medium in 1988 appears only in Nikkei xTECH. Single-source detail.
- Halzen's age of 82 appears only in Mainichi. Single-source detail.
What local media are saying
Timeline, local time
- Jiji Press publishes a first report that a researcher from the IceCube neutrino experiment has won this year's Nobel Prize in Physics. [ 1 ]
- Yomiuri publishes a report including a comment from Hiroshima University professor Taiji Fukazawa on what the IceCube observation means for high-energy cosmic ray research. [ 2 ]
- Nippon TV News reports the award to Halzen and details the IceCube project, including Chiba University's participation and the December ceremony in Stockholm. [ 3 ]
- Sankei reports the Royal Swedish Academy of Sciences announcement, the citation, the 23 September 2017 Japan-time neutrino detection and the prize sum. [ 4 ]
- Mainichi reports the award, saying Halzen is 82 and that IceCube began construction in 2005 and was fully operating in 2011. [ 5 ]
- Tokyo Shimbun carries a Stockholm-datelined report on the Nobel Prize for the South Pole particle observation and the IceCube international research project. [ 8 ]
- Nikkei reports that researchers from Chiba University, which takes part in IceCube, held a press conference in Chiba and welcomed the award. [ 11 ]
- Nikkei xTECH reports the award and technical background, including Halzen's 1988 proposal and the detection of 28 high-energy neutrinos by 2013. [ 16 ]
- Asahi Shimbun publishes an explainer on the IceCube experiment, why it is at the South Pole, Chiba University's contribution and the potential uses of neutrino observation. [ 19 ]