Nobel Prize in physics awarded for bizarre neutrino discovery

The Nobel Prize in physics is awarded to two researchers who found that neutrinos change flavors as they travel.

Courtesy of The T2K Collaboration
Neutrinos in the sun mapped by the Super-Kamiokande experiment.

Takaaki Kajita and Arthur B. McDonald will share this year's Nobel Prize in physics for helping to reveal that subatomic particles called neutrinos can change from one type to another — a finding that meant these exotic particles have a teensy bit of mass.

Neutrinos are the second-most abundant particles in the cosmos, constantly bombarding Earth. (Photons, or particles of light, are the most numerous.) The tiny particles come in three flavors: electron, muon and tau. In their separate experiments, Kajita and McDonald each showed that neutrinos change between certain flavors — a process called neutrino oscillation.

"The discovery has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe," representatives of the Nobel Foundation said in a statement about this year's Nobel Prize in physics.

In 1998, Kajita presented research that showed that muon-neutrinos created by reactions between the atmosphere and cosmic rays changed their identities as they traveled to the Super-Kamiokande detector, buried in a zinc mine, about 155 miles (250 kilometers) northwest of Tokyo. [5 Mysterious Particles Lurking Underground]

In 2001, McDonald and his team announced that they had discovered that electron-neutrinos from the sun changed flavors into muon- or tau-neutrinos on their way to the Sudbury Neutrino Observatory in Canada.

Neutrinos very rarely interact with matter; they can zip through a block of lead a light-year across. Large underground detectors, like the ones in Japan and Canada, are needed to observe such rare interactions with matter.

The Nobel Prize-winning discoveries have far-reaching implications, scientists with the Nobel Foundation say. For instance, they could help physicists figure out the matter-antimatter puzzle: Scientists think that during the Big Bang, equal amounts of matter and its weird cousin antimatter were produced; smash-ups with matter destroyed most of this antimatter, leaving a slight excess of matter in the universe.

Physicists are still unsure why matter won this cosmic clash. One way to solve the puzzle would be to find matter behaving differently from antimatter; flavor-changing neutrinos could be one way to see this difference.

In addition, neutrinos would not be able to oscillate, or change their identities, if they had zero mass, physicists say. Therefore, the experiments by Kajita and McDonald also uncovered neutrinos' slight mass.

Kajita, like most Nobel Prize winners, was surprised to get the call this morning letting him know of his achievement. When Adam Smith of the official Nobel Prize website asked Kajita if he'd ever dreamed of this moment, he responded, "Well, of course, well, as really a dream, maybe years, but not serious dreaming so far."

Kajita, of the University of Tokyo in Kashiwa, Japan; and McDonald, of Queen's University, in Kingston, Canada, will share the Nobel Prize amount of 8 million Swedish krona (about $960,000).

Yesterday, the Nobel Foundation announced the Prize in physiology or medicine to a trio of scientists for discovering novel treatments for parasitic infections. Tomorrow (Oct. 7), the Nobel Prize in chemistry will be announced.

Follow us @livescienceFacebook & Google+. Original article on Live Science.

Copyright 2015 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.