Physics Nobel Prize Proves Neutrino Isn’t Massless

On Tuesday, Japan’s Takaaki Kajita and Canada’s Arthur B. McDonald were awarded the Nobel for their discovery of neutrino oscillations which showed that neutrinos have mass. Now, the two experiments discovered that the neutrinos had changed identities. This phenomenon, called neutrino oscillation, is possible only if neutrinos have mass.

Two scientists have won the Nobel Prize in Physics for their groundbreaking work showing that neutrinos – electrically neutral subatomic particles – have mass, contrary to what had been thought.

Mr. McDonald is a professor emeritus at Queen’s University in Kingston, Canada. 47 have been given to one Laureate only, and just 2 women have been awarded the Physics Prize so far – including Marie Curie.

A neutrino puzzle that physicists had wrestled with for decades had been resolved. Others are produced in nuclear reactions inside the Sunday. They found the located within easy reach of Sudbury /Ontariomit Sudbury Neutrino Observatory (SNO) strong evidence that electron neutrinos caused by nuclear fusion inside the sun can change their identity, on its way to Earth by itself.

Their work had solved a puzzling observation that compared to theoretical calculations of the number of neutrinos expected to be bombarding the Earth, up to two thirds were apparently missing from measurements. Nonetheless the discovery that receives this Nobel Prize is a groundbreaking one.

“On behalf of all Canadians, I congratulate Arthur B. McDonald on co-winning this year’s Nobel Prize in Physics, sharing the prestigious worldwide honour with Japanese scientist Takaaki Kajita“, said Prime Minister Stephen Harper.

McDonald told a news conference in Stockholm by telephone that this not only gave scientists a more complete understanding of the world at a fundamental level but could also shed light on the science behind fusion power, which drives the Sun and could one day be tapped as a source of electricity on Earth.

Kajita’s mentor was Masatoshi Koshiba, distinguished professor of the University of Tokyo.

McDonald will share the prize with Takaaki Kajita of the University of Tokyo. At depths of a kilometer or more, thousands of sensors at each facility are shielded from cosmic rays, allowing them to focus on detecting neutrinos’ behavior.

Next, the researchers will aim to capture neutrino particles and examine their properties.

“It changes our understanding of the fundamentals of particle physics, and particles make up everything in the universe”, said Robert G.W. Brown, chief executive officer of the American Institute of Physics.

On Monday the Nobel Prize in medicine went to scientists from Japan, the USA and China who discovered drugs that are now used to fight malaria and other tropical diseases.

In the coming days, the Nobel committee also will announce prizes in chemistry, literature, peace and economics.