What he and Arthur B. McDonald had discovered was oscillations of elusive particles called neutrinos. In the Japanese underground observatory Kamiokande the research group led by Kajita could register the oscillations which showed that the particles, assumed to be massless, actually have mass. The discovery has had profound implications on for example stellar structure and cosmology.
“Neutrinos are extremely fascinating particles, the second most common (after photons) in the Universe but so elusive that we have a hard time noticing their presence. They are potentially the key to understand some of the deepest questions that still remain unsolved,” says Professor Thomas Nilsson, experimental physicist and Head of the Department of Physics at Chalmers.
Neutrinos were created at the birth of the Universe. Today they are created in nuclear processes – in the Cosmos, in our laboratories and in nuclear reactors.
“When I joined Kamiokande, underground experiments were just a very small sub-field of particle physics experiments. At present, after more than 30 years, these underground experiments have become some of the most promising, powerful, versatile, and efficient ways to explore both particle physics and the Universe itself. This research underground continues to stimulate my interest. I look forward to what new discoveries the future will hold,” writes Professor Takaaki Kajita in The Nobel Prizes 2015, published on behalf of The Nobel Foundation.
At Chalmers, many researchers are looking forward to Professor Kajita’s visit, especially physicists within astro, particle and subatomic physics.
“I’m very glad for this event for several reasons. I studied particle physics as a student, but ended up as a reactor physicist, which is a completely different area. Nevertheless, both the existence of neutrinos, as well as two out of the three possible neutrino oscillations were proven by using neutrinos from nuclear reactors,” says Professor Imre Pázsit at the Department of Physics at Chalmers.
Due to this fact, and to his extensive collaboration with Japanese physicists, Pázsit got into contact with the neutrino research quite some time ago. He met Professor Kajita in Stockholm in connection to the Nobel ceremony and at the Nobel Dialogue Dinner in Tokyo last year they met again.
“There I understood his interest to visit Sweden again, which of course helped to invite him to Chalmers. I look forward to his lecture and I hope that many will take the opportunity to listen to a fascinating talk,” says Professor Pázsit.
Imre Pázsit has collaborated with Japanese researchers for more than 25 years. In 2016 he was awarded the Order of the Rising Sun for his "Contribution to the promotion of scientific and technological exchanges and mutual understanding between Japan and Sweden".
Image credit: Bengt Nyman, Wikimedia commons
The lecture by Professor Takaaki Kajita will be open to the public, free of charge and held in Gustaf Dalén lecture hall at Chalmers campus Johanneberg, Gothenburg on 28 November at 15.15-16.00.
No registration is needed.
The Nobel Prize in Physics for 2015: Metamorphosis in the particle world
The Nobel Prize in Physics 2015 recognises Takaaki Kajita in Japan and Arthur B. McDonald in Canada, for their key contributions to the experiments which demonstrated that neutrinos change identities. This metamorphosis requires that neutrinos have mass. The discovery has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe.
Takaaki Kajita, Super-Kamiokande Collaboration, University of Tokyo, Kashiwa, Japan and Arthur B. McDonald, Sudbury Neutrino Observatory Collaboration, Queen’s University, Kingston, Canada, were awarded “for the discovery of neutrino oscillations, which shows that neutrinos have mass”