…. or, to be more precise, to their investigators.
As announced today, October 6, on the official webpage, “The Nobel Prize in Physics 2015 was awarded jointly to Takaaki Kajita and Arthur B. McDonald for the discovery of neutrino oscillations, which shows that neutrinos have mass.”
First detected in 1956 by Fermi (after 20 years of chasing), the elusive neutrinos are among some of the most abundant inhabitants of the Universe and the majority of them was born around 15 billions years ago, soon after the Big Bang. Plainly speaking, they are subatomic particles produced by the decay of radioactive elements and their characteristics is that they lack an electric charge, in addition of being “…the most tiny quantity of reality ever imagined by a human being” (F. Reines).
Since its discovery, a lot of efforts (you can read about them here) have been made to study their somehow baffling characteristics (for example, unlike photons or other charged particles, they can travel across the universe without interference, being not affected by interstellar magnetic fields, or disturbed by matter) which make them at the same time fundamental for the investigation of the universe but also extremely challenging to detect. One of the many attempts at detection is the series of experiments conducted at Sudbury Neutrino Observatory (SNO) for solar neutrino experiment, run by Prof. McDonald.
(Credit: SNOLAB website)
What is this discovery just rewarded with the 2015 Nobel Prize about? It solves an important question that since the beginning of the 1990s has puzzled researchers – namely the fact that fewer neutrinos were detected than the ones expected applying theoretical models: the point was to find out what happened to the rest of them. Now Kajita and McDonald seem to have found the reply: neutrinos switch identity, so to speak, like some shape-shifter fantasy creatures.
This also means that, in addition to that, neutrinos must have a mass, in blatant contradiction with the Standard Model of particle physics and with huge consequences on the nature and future of the Universe.
“The discovery of neutrino masses and of neutrino oscillations are the first cracks in the Standard Model of particle physics. The era of exciting discoveries in neutrino physics has only just begun” (Prof. Stefan Soldner-Rembold, University of Manchester, UK, BBC News, 6 October 2015).
Watch the 2015 Nobel Prize Announcement here: