Fermilab's NOvA Experiment Records First Evidence Of Oscillating Neutrinos
Scientists involved in the NOvA (NuMI Off-Axis Electron Neutrino Appearance) research project at Fermilab, which specializes in high energy particle physics, have found the first evidence of oscillating neutrinos.
The results showed that the detector made for the project works and is actually making progress towards a better understanding of the mysterious particle.
Neutrinos interact but only very weakly with ordinary matter. The elusive particle comes in three types namely tau neutrinos, electron neutrinos and muon neutrinos. The subatomic particles are produced by sources ranging from the sun, the Big Bang and nuclear power reactors.
Since neutrinos oscillate, they can change from one type into another. Among the objectives of the NOvA project is to observe oscillations of muon neutrinos into electron neutrinos.
"We make a beam of muon-type neutrinos at Fermilab, and then we detect those at Ash River, Minnesota," explained Patricia Vahle, from William & Mary. "We are looking for muon-type neutrinos to change into electron-type neutrinos. We also look for those muon neutrinos to just disappear, or really change into any type of neutrino."
The first results of the experiment, which were released at the American Physical Society's Division of Particles and Fields conference in Ann Arbor, Michigan this week, confirmed that the massive particle detector that was used for the experiment can detect neutrinos that are fired from 500 miles away.
Scientists have recorded the neutrino interaction in the far detector in Ash River, Minnesota since February last year with the researchers monitoring the data remotely.
The composition of the neutrino beam that was generated at Fermilab is measured while the beam passes through a near detector located underground. The particles then travel over 500 miles changing types along the ways.
Trillions of neutrinos are being sent by Fermilab's accelerator about once per second but because neutrinos interact so rare, only a few are registered at the far detector.
A signature trail of particles and light is released when a neutrino interacts with an atom in the far detector and this will indicate what type of neutrino it is. Most of the beam coming from Fermilab is made up of muon neutrinos.
Scientists predicted that they would see 201 muon neutrinos at the far detector if oscillations did not occur but they only saw 33, which proves that the muon neutrinos have transformed into two other types.