2105 Nobel
Prize in Physics winners have strong ties to the University of Hawai‘i
The Royal Swedish Academy of Sciences has announced that the Nobel
Prize in Physics for 2015 is going to two scientists for their key
contributions to two experiments elucidating peculiar properties of subatomic
particles known as neutrinos. Takaaki Kajita of the University
of Tokyo in Japan and Arthur B. McDonald of Queen’s University in Canada
both have important connections to the University of Hawai‘i.
According to the Royal Swedish Academy of Sciences, Kajita’s
and McDonald’s experiments demonstrated that neutrinos change identities
and have mass. “The discovery
has changed our understanding of the innermost workings of matter and can prove
crucial to our view of the universe,” the academy said in a release. The results, along with subsequent
others have now made clear that these ghostly neutrinos have the property of
changing from one type or flavor to another as they fly, penetrating matter with
almost no attenuation, characteristics unlike any other particle, and not
predicted by the Standard Model of elementary particle physics. These results have initiated what many
call the neutrino revolution over the last two decades, with many new experiments,
theoretical speculations and surprising results.
Since 2010, Art McDonald has been an affiliate professor in the
Department of Physics and Astronomy at the University of Hawai‘i at Mānoa. He
typically spends about three months every year at UH Mānoa
giving seminars and colloquia and brainstorming on neutrino physics and dark
matter with members of the university’s high energy physics group, and
talking physics with the nanoparticle group too. McDonald has led the SNO group which in
the late 2001 demonstrated that neutrinos produced in the core of the Sun
changed identity by the time they arrive at the Sudbury Neutrino Observatory in
Canada. These convincing data
presented the long awaited solution to “solar neutrino puzzle” an
outstanding conundrum since the late 1960’s…. that electron
neutrinos made in the sun were being changed to a combination of electron, muon
and tau neutrinos by the time they arrived at earth. Further information is at the SNO
website https://www.snolab.ca/
Earlier, in June 1998, Tataaki Kajita presented the discovery that muon type neutrinos
from the atmosphere switch identities while traversing the earth (muon
neutrinos changing to mostly a combination of muon and tau neutrinos), based on
new data from the Super-Kamiokande giant underground detector in Japan, a
collaboration about 100 of mostly Japanese and US scientists. He was the leader of the analysis group
which extracted the dramatic results.
Early analysis of this work was carried out by University of Hawai‘i
Professor John Learned and students.
UH physics PhD student John Flanagan wrote the first dissertation
including the Super-Kamiokande’s groundbreaking
results in 1997. The UH team at that time included Dr. Shige Matsuno and the
late Prof. Vic Stenger. Analysis methods developed by
UH have become standard in the field of neutrino oscillations, and ongoing
results from Super-Kamiokande continue to refine the detailed understanding of
the oscillations and related phenomenon. More information is available at the
Super-Kamiokande website: http://www-sk.icrr.u-tokyo.ac.jp/sk/index-e.html
The present UH experimental neutrino research team consists as well of
Profs. Jelena Maricic, Peter Gorham, and Gary Varner plus 15 students and postdocs, with a total grant income of about $2.5M per
year. The theory work of UH Professor Sandip Pakvasa and colleagues, Profs.
Tata, Kumar and Marfatia in the UH High Energy
Physics group have been closely associated with both the Super-Kamiokande and
Sudbury Neutrino Observatory efforts.
Discovery of Neutrino
Oscillations and Mass
The
following information relating to the Super-Kamiokande Collaboration June 1998
announcement of the discovery of muon neutrino oscillations, and thereby
neutrino mass. The postings herein are a bit dated, though the conclusions
remain valid and even strengthened with time.
Some more
details:
- Story of Muon
Neutrino Oscillations Discovery,
updated 2015
- Timeline of Events in the History
of Neutrino Study
Some graphical
material:
- Graphic
Illustration of Neutrino Oscillations through Earth, .eps
731K file
- Graphic
Illustration of Neutrino Oscillations through Earth, .gif 69K file
- Graphic
Illustration of SuperKamiokande Detector, .eps 277K file
- Graphic
Illustration of SuperKamiokande Detector, .gif
133K file
- Graphic
Illustration of SuperKamiokande Detector, .jpg
68K file
- Photo
of some of the 1998 UH Neutrino Hunters and a 20 inch PMT, .jpg 92K file
- Photo
of PMT, .jpg 47.5K
Historical Material:
·
Official SuperK News
Release from Takayama, Japan
·
UH News Q and A,
Lay Version
Technical
Material: