• 15.04.2020
  • Press release
  • University of Geneva

T2K Results Restrict Possible Values of Neutrino CP Phase

Published in Nature, the results are a major step forward in the study of difference between matter and antimatter

Intérieur du détecteur Super Kamiokande, construit sous une montagne au Japon. Photo de 2006.
Image: Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo
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Intérieur du détecteur Super Kamiokande, construit sous une montagne au Japon. Photo de 2006.
Intérieur du détecteur Super Kamiokande, construit sous une montagne au Japon. Photo de 2006. (Image: Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo)

The T2K Collaboration has published new results showing the strongest constraint yet on the parameter that governs the breaking of the symmetry between matter and antimatter in neutrino oscillations.

Professor Federico Sanchez (University of Geneva), spokesperson of the T2K Experiment, comments on the T2K publication about the indication of the matter-antimatter symmetry violation in neutrinos: "These results indicate that CP violation in neutrino mixing may be large, and T2K looks forward to continued operation with the prospect of establishing evidence for CP violation in neutrino oscillations."

The results show the strongest constraint yet on the parameter governing CP violation in neutrino oscillations, one of the few parameters governing fundamental particle interactions that has not yet been precisely measured.

Prof. Sanchez underlines the full team effort to obtain this results: "These exciting results are thanks to the hard work of hundreds of T2K collaborators involved in the construction, data collection and data analysis for T2K over the past two decades."

The full press release from the experiment can be found in the T2k website and in the Nature article.

  • Associations

Artistic representation of a proton decay. Illustration: Hyper-Kamiokande Collaboration
  • 18.11.2019
  • CHIPP
  • News
  • Press release

Visiting the Japanese Super-Kamiokande detector (part 2)

In deep underground tunnels of former mines near the Japanese Alps, teams of scientists with Swiss participation are researching various types of elementary particles. Over the next few years, powerful research instruments will be put into operation with which scientists want to discover the nature of neutrinos. The hoped-for results could lead to solving of deep puzzles in our understanding of the universe.
A 1.7 km long tunnel leads to the neutrino detector Super-Kamiokande. Photo: B. Vogel
  • 11.11.2019
  • CHIPP
  • News
  • Press release

Visiting the Japanese Super-Kamiokande detector (part 1)

Hardly any elementary particle occurs more frequently in the universe than the elusive neutrino. The investigation of the almost massless tiny particle is a focus of current elementary particle physics. Perhaps the most important contribution to the understanding of neutrino has been made over twenty years by the Japanese Super-Kamiokande detector, in which several Swiss research groups are involved. A visit to the Japanese mountains.
Prof. Alain Blondel with the Gargamelle bubble chamber on the CERN site in Meyrin: With Gargamelle, "neutral currents" were discovered at CERN in 1973, a rare interaction between neutrinos and matter.
  • 02.10.2017
  • CHIPP
  • News

Why half the universe is missing

In 2012, the Higgs particle was detected by the ATLAS and CMS experiments at CERN. Since then, one often hears that the Standard Model of particle physics is complete. "Not quite true!" says Alain Blondel, professor of physics at the University of Geneva. There is still the neutrino, which, as it is known today, does not fit into the Standard Model. Exciting news about the elusive particle was published recently: New observations by the T2K neutrino experiment in Japan provide first indications shedding light to a central question of modern physics: Why does the universe consist only of matter while the associated antimatter is missing?
T2K experiment in Japan
  • 04.08.2017
  • CHIPP
  • News

T2K presents hint of CP violation by neutrinos

The international T2K Collaboration strengthened its previous hint that the symmetry between matter and antimatter may be violated for neutrino oscillation.

Tags

  • Physics
  • Elementary particles
  • Particle Physics