Neutrinos are one of those few unlucky sub atomic particles which never get any attention whatsoever. The have zero or no mass ,travel at the speed of light and interact with nothing. Every second 50 trillion are passing through the human body. They are the residues of more important reactions like beta decay, nuclear fusion, particle collisions etc. Nobody cares about neutrinos. Well thats about to change. With a new discovery , they may hold the secret towards one of the biggest mysteries- Dark Matter.
Neutrinos come in 3 types or “flavors” -electron neutrino, muon neutrino and tau neutrino depending upon their mode of creation. for example electron neutrinos are usually generated when protons change to neutrons. The standard model of physics assume that neutrinos have no mass and cant change flavor. The controversy started when we started counting the no of neutrinos of a particular flavor arriving from the Sun to earth. They differed from predicted value by 30-50 %.Standard Model cant account for this change. This has been referred to as the solar neutrino problem.
For the past three years, CERN has fired a beam of muon neutrinos (one of the kinds that fall out of decaying muons) from Geneva, Switzerland to the OPERA experiment in a laboratory near Italy’s Gran Sasso mountain. After three years and billions of billions of muon neutrinos in and muon neutrinos out, for the first time, the OPERA physicists saw something else arrive in Italy. After the 450-mile, 2.4-millisecond voyage, a muon neutrino appears to have transformed into a tau neutrino. Researchers are 98 percent sure that this is true neutrino oscillation.
This kind of oscillation between different flavors requires the neutrinos to have mass, in opposition to the standard model. If neutrinos do have mass this could explain some of what cosmologists call dark matter- the mass that should exist in the universe that cant be found. Let see.
“Whatever exists in the infinitely small always has repercussions in the infinitely big.”