New Results from T2K Conclusively Show Muon Neutrinos Transform to Electron Neutrinos!

Photo: A 3D view of a candidate electron-neutrino event in the Super-Kamiokande detector.

 

July 19th, 2013: Today at the European Physical Society meeting in Stockholm, the international T2K collaboration announced definitive observation of muon neutrino to electron neutrino transformation. In 2011, the collaboration announced the first indication of this process, a new type of neutrino oscillation.  At that time, there was less than a 1% chance that the result could have been due to a statistical fluctuation. Today, with 3.5 times more data, this transformation is firmly established. The probability that a random statistical fluctuations alone would produce the observed excess of electron neutrinos is less than one in a trillion.  Stated in language of statistics, a statistical fluctuation is ruled out at the 7.5 sigma level; this is above the 5 sigma threshold particle physicists use to claim discoveries. This T2K observation is the first of its kind in that an explicit appearance of a unique flavor of neutrino at a detection point is unequivocally observed from a different flavor of neutrino at its production point.  The T2K experiment expects to collect 10 times more data in the near future, including data with antineutrino beam for studies of CP violation in neutrinos. You can read more about this result on Prof. Chris Walter's web site. You can read the official T2K press release with other information here. Professors Kate Scholberg and Chris Walter have been working on the Super-K or T2K experiment for over 15 years.  Other current members include Postdocs Tarek Akiri and Alex Himmel along with graduate student Taritree Wongjirad. Recent past members include former graduate student Josh Albert and former postdoc Roger Wendell who is now a faculty member at the University of Tokyo.