News

T2K submits paper that conclusively shows muon neutrinos transform to electron neutrinos

December 3, 2013

The T2K experiment has submitted a paper to Physical Review Letters, reporting the definitive observation of electron neutrino appearance in a high-purity muon neutrino beam that travels 295 km, from the J-PARC accelerator complex to the Super-Kamiokande underground neutrino detector. A total of 28 electron neutrino events were detected, compared to 4.92 ± 0.55 background…

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New results from T2K conclusively show muon neutrinos transform to electron neutrinos

July 19, 2013

Electron-neutrino candidate in Super Kamiokande

Today at the European Physical Society meeting in Stockholm, the international T2K collaboration announced a definitive observation of muon neutrino to electron neutrino transformation. In 2011, the collaboration announced the first indication of this process, which was then a new type of neutrino oscillation; now, with 3.5 times more data, this transformation is firmly established…

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T2K receives a prize from a French science magazine

November 9, 2012

T2K has been awarded a prestigious prize by La Recherche, a French science magazine. This prize is called “Le Prix La Recherche” and has 12 categories including biology, chemistry, mathematics and medicine. T2K received the physics prize for finding the first indications of oscillations from muon neutrinos to electron neutrinos. Some T2K collaborators can be…

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T2K updates its electron-neutrino appearance result using its full dataset obtained by summer 2012

October 23, 2012

The T2K collaboration presented new results on oscillations from muon neutrinos to electron neutrinos at the 2012 International Conference on High Energy Physics in Melbourne, Australia. These oscillations are predicted by quantum physics if neutrinos have non-zero masses. The new results were obtained with more than twice as much data as the T2K paper published…

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T2K Presents New Results that confirms their Electron Neutrino Appearance Results published in July 2011

June 5, 2012

At the 2012 Neutrino conference in Kyoto, Japan, the T2K collaboration presented new results on electron neutrino appearance from muon neutrino that confirmed their previous published results in PRL, in July 2011, which reported the first single experimental indication that θ13 is non-zero and large with a 2.5 σ level of significance. Based on the…

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First T2K beam neutrino event in Super-Kamiokande since March 2011 earthquake

February 3, 2012

The first T2K beam neutrino event since the earthquake of March 2011 was seen in Super-Kamiokande (T2K’s far detector) on 26th Janaury 2012. It is shown in the event display above, and has a Cherenkov ring produced by a muon in the centre of the image. This muon was produced when a muon neutrino in…

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T2K publishes first off-axis measurement of muon-neutrino disappearance

January 18, 2012

T2K has published the first measurement of muon-neutrino disappearance by an off-axis experiment in Physical Review D at http://prd.aps.org/abstract/PRD/v85/i3/e031103. The T2K beam is mostly composed of muon neutrinos, and 104 muon-neutrino events would have been expected in T2K’s far detector Super Kamiokande if there were no neutrino oscillations. However only 31 such events were observed,…

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T2K makes the Top Ten !

January 18, 2012

Physics World, the magazine of the Institute of Physics in the U.K., has included one of T2K’s results in its top ten scientific breakthroughs of 2011. T2K was included for finding the first indications for oscillations from muon neutrinos to electron neutrinos as described here. Six electron-neutrino events were seen in Super Kamiokande (T2K’s far…

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First test run of beams in J-PARC proton accelerator since earthquake

January 14, 2012

The proton accelerator at J-PARC (Japan Proton Accelerator Research Complex) in Tokai, Japan was affected by the earthquake of March 2011, though not by the tsunami. The damage sustained during the earthquake has now been mostly repaired, and the first test run of proton beams since the earthquake was successfully conducted in the LINAC (linear…

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Status of recovery work since the earthquake

January 14, 2012

After several months of recovery work since the earthquake, we succeeded in taking the proton beam from Dec.24,2011 as scheduled and successfully confirmed the functionality of the beam line components and the reproducibility of neutrino production. However, on Dec.22, during the final operation test, switching devices called IGBTs in the horn power supply were broken.…

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