Nobel Prize Physics 2015: 2 Scientists Solve The Neutrino Problem

He joined the University’s physics department to conduct research on particle physics. We have been able to detect neutrinos emerging from the center of an exploding star more than a hundred thousand light-years away. A neutrino that, say, starts out as an electron neutrino can evolve into a muon neutrino, and then switch back again.

In MINOS, or Main Injector Neutrino Oscillation Search, the Fermilab outside Chicago shoots an underground neutrino beam 450 miles way to a detector located half a mile down in a old iron mine in Minnesota.

Neutrinos are very weird particles. In a single stroke, it both solved a long-standing puzzle about these most elusive of fundamental particles and also exposed an incompleteness in the current bedrock theory of physics, called the standard model. In layman’s terms, his discovery demonstrates that neutrinos hold mass. They come in three types, called flavors – electron, muon and tauon neutrinos, corresponding to the three charged particles they pair with – and all of these seem to be stable, unlike the heavy cousins of the electron.

Leading a team comprising researchers from different nationalities and universities, Kajita steadily observed neutrinos falling from outer space at the Super-Kamiokande.

Takaaki Kajita and Arthur McDonald’s breakthrough was the discovery of a phenomenon called neutrino oscillation that has upended scientific thinking and promises to change understanding about the history and future fate of the cosmos.

RAY VOLKAS: Well the precise mechanism by which neutrinos would gain mass, so you can just put mass by hand into the theory, there has to be a mechanism by which they get mass. That mechanism is unknown, and it can have all sorts of implications depending upon what it exactly is and there are many possibilities. So, if particles come into a collision with a given initial energy (which includes their mass from the E=mc relation), they need to have the same total energy after the collision. This suggested that electron neutrinos can, in fact, oscillate into other neutrinos. The neutrinos that Davis detected were emitted by nuclear reactions at the very center of the sun, escaping this incredibly dense, hot place only because they so rarely interact with other matter.

Experiments showed that only a third of those neutrinos from the sun that were expected to be on earth were actually being found, which led to the conclusion that the other two-thirds were changing types. However, as always, these new insights led to further questions. What we learn about the matter/antimatter asymmetry could change our very understanding of how the universe evolved to the present day.

One of the most promising ideas ties the oscillation of neutrinos with the fact that our universe exists at all.

As it were, the stuff that we are made of – common matter – is just 5 for each penny of reality. We believe their mass is generated differently. So where did all the anti-matter go?

It’s a mystery why neutrinos are nearly, but not quite, massless.

That is the reason Canada, alongside partners in nations around the globe, are building extraordinary gadgets, for example, the Sudbury Neutrino Observatory and the Super Kamiokande Detector in Japan, to attempt to catch these ethereal particles to comprehend what the universe is really made of.

Until around 2000, it was thought that the ghost-like neutrinos could be this dark matter, but we now know that they are not heavy enough. We do know why they’re nearly noninteracting, though: They don’t feel the electromagnetic or strong forces that bind nuclei and atoms, only the aptly named weak force (and gravity, but barely, because their masses are small).