From The New York Times, April 15, 2020: An international team of 500 physicists from 12 countries, known as the T2K collaboration, reported that they had measured a slight but telling difference between neutrinos and their opposites, antineutrinos. Fermilab Deputy Director Joe Lykken comments on the result and how the international Deep Underground Neutrino Experiment, hosted by Fermilab, may be able to make a definitive discovery of CP violation.
antineutrino
Fermilab’s NOvA neutrino experiment records in its giant particle detector the passage of slippery particles called neutrinos and their antimatter counterparts, antineutrinos. Famously elusive, these particles’ interactions are challenging to capture, requiring the steady accumulation of interaction data to be able to pin down their characteristics. With five years’ worth of data, NOvA is adding to scientists’ understanding of neutrinos’ mass and oscillation behavior.
Scientists working on the MINERvA experiment at Fermilab have examined a few ways neutrons can affect the measurements of antineutrino interactions.
From The News Recorder, June 6, 2018: Scientists on Fermilab’s NOvA experiment — the world’s largest-baseline neutrino experiment — have detected strong evidence of muon antineutrinos oscillating into electron antineutrinos. Such phenomenon has never been observed before.
Fermilab’s MINERvA experiment gives a boost to the particle physics field by sharpening a model of a frequent, pesky phenomenon.
The amount of time a neutrino has to oscillate is directly related to the distance the neutrino travels and the energy of the neutrino itself. Measuring the distance is easy. The hard part is measuring the neutrino energy.
The observation occurred just two hours after the lab’s accelerator complex switched to antineutrino delivery mode.
MINERvA measures the total probability that a muon neutrino (or antineutrino) interacts with the protons and neutrons inside the MINERvA detector via charged-current interaction.
The observation of the appearance of an electron neutrino proves conclusively that the NOvA experiment can measure electron neutrino appearance and confirms oscillations at greater than 3 sigma with primary analysis or 5 sigma with secondary analysis.
The physics community got a jolt last year when results showed for the first time that neutrinos and their antimatter counterparts, antineutrinos, might be the odd man out in the particle world and have different masses.