Arthur McDonald Current Affairs - 2019
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Takaaki Kajita (Japan) and Arthur B. McDonald (Canada) have jointly won the prestigious 2015 Nobel Prize in Physics.
The Royal Swedish Academy of Sciences has selected them for their key contributions to experiments showing that neutrinos change identities. They individually have discovered neutrino oscillations and shown that neutrinos have mass.
Mr. McDonald is a professor emeritus at Queen’s University in Kingston, Canada. He had led a research group which had demonstrated that the neutrinos from the Sun were not disappearing on their way to Earth. The group had captured these neutrinos with a different identity at the Sudbury Neutrino Observatory (Canada).
Takaaki Kajita is from the University of Tokyo, Japan. He had discovered that neutrinos from the atmosphere switch between two identities when they reach earth and after were captured by Super-Kamiokande neutrino detector (Japan).
- Neutrinos were first proposed by Swiss scientist Wolfgang Pauli in 1930. They are electrically neutral, weakly interacting elementary subatomic particle with half-integer spin.
- They are the second most widely occurring particle in the universe after photons which are the particles makingg up light.
- It belongs to the lepton family. There are three types of neutrinos: electron neutrinos (ve), muon neutrinos(vu) and tau neutrinos(vT) differing in terms of mass.