2015 Nobel Prize in Physics awarded to Takaaki Kajita



Takaaki Kajita, Kavli IPMU PI Credit: Kavli IPMUTakaaki Kajita, Kavli IPMU PI
Credit: Kavli IPMU
The 2015 Nobel Prize in Physics has been awarded to Takaaki Kajita, Director of the University of Tokyo Institute for Cosmic Ray Research and Kavli IPMU Principal Investigator. Congratulations! This year’s prize recognizes the work carried out on atmospheric neutrino oscillations at the Kamiokande and Super-Kamiokande detectors in Kamioka, central Japan, which produced definite proof that neutrinos have mass.


Kavli IPMU Director Hitoshi Murayama's comment on today's Nobel Prize: 

"I've always believed that Kajita's discovery in 1998 should be awarded Nobel Prize in Physics. All Nobel Prizes in particle physics so far were given to achievements that led to the establishment of the theory called 'Standard Model'. On the other hand, Kajita, and the joint awardee Art McDonald, have shown for the first time in history that the Standard Model cannot explain everything in the Universe. Their work is historic in that they have shown that the Standard Model is not the ultimate goal, but rather needs to be expanded to a yet bigger framework. Actually there is a long-standing problem 'Why do we exist in the Universe? Universe created matter and anti-matter one to one, but somehow the balance was tilted towards matter at the level of one part in billion, so that matter and anti-matter did not completely annihilate each other and a small amount of matter remained to date. How was the balance changed? This is literally a matter of life and death for us. Now that they discovered that the neutrinos have tiny amount of mass, there is a very strong anticipation in the community that neutrino is our 'father' who protected us from the complete annihilation, by tilting the balance between matter and anti-matter. This is a theory put forward by Fukugita and Yanagida at Kavli IPMU, but it became very plausible after Kajita's discovery. As a matter of fact, this research is pursued by the Hyper-Kamiokande proposal in Japan, and particle physics in the US puts research in this area as its first priority. Clearly Kajita's work changed the direction of research in particle physics worldwide."

 Hiroo Imura, the chairman of WPI Program committee, congratulates Takaaki Kajita on his Nobel Prize.
(Please refer to the following JSPS website for Dr. Imura's comment)

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