A Fermilab First: Detecting Oscillating Neutrinos

An announcement at last week's American Physical Society's Division of Particles and Fields conference revealed that Fermilab's NOvA experiment has for the first time observed oscillating neutrinos, which have long been predicted but -- as a case even more special than observing neutrinos in general, not an easy task -- never before detected. The research team fired trillions of of muon neutrinos from an accelerator at the Fermilab, outside Chicago. The neutrinos travel 500 miles through Earth's crust to a detector at Ash River, Minnesota. There, scientists were able to filter through millions of cosmic ray strikes and hone in on neutrino interactions. The arriving neutrinos featured some electron neutrinos, suggesting they had oscillated along their path through Earth. "Basically, it shows that we know what we're doing," said Patricia Vahle, associate professor of physics at the College of William & Mary.

Comments

Summary is kind of deceptive.

[Anonymous Coward]

Actually, oscillating neutrinos have been detected before. They just were from the sun, not human made. https://en.wikipedia.org/wiki/...

Summary is Wrong, Article technically Correct

[Roger W Moore]

Actually the summary is wrong. Neutrino oscillations have been detected before from atmospheric neutrinos, solar neutrinos and beam neutrinos (e.g. the T2K experiment). The linked article technically gets it right, but is somewhat misleading, calling it "our first observation" where 'our' refers to the Nova experiment and not humanity in general i.e. it is the first time that the Nova experiment has detected oscillating neutrinos.

This is an important milestone for them but just indicates that their detector works in much the same way that we measured known Standard Model processes at the LHC before going after the higgs boson. If you can't see the physics that we know is there first nobody will believe you if you claim to see something new. Hopefully this is just the precursor for some interesting results from Nova...and hopefully they can get the Fermilab PR machine to write less misleading/hyped press releases when they do have some exciting results to announce!

Possible but Massively Impractical

[Roger W Moore]

Can those neutrino oscillations be modulated at will so as to transfer data?

Technically yes they could. When neutrinos pass through matter the electron-neutrino part of them interacts differently to the muon and tau parts because matter contains electrons (something called the MSW effect). However because at typical energies neutrinos interact only very weakly with matter the effect is very tiny and so far is only significant when neutrinos pass though objects like the Earth or the Sun. This means that you would need an extraordinarily sensitive detector, very high energy neutrinos [at energies 1000+ times greater than the LHC neutrinos start to interact a lot more readily with matter] and/or an incredibly intense neutrino beam.

A better way to modulate the neutrino beam would be to change the way it is generated assuming it is created from an accelerator. By altering the polarity of the magnets selecting the muons which then decay you could flip the beam back and forth between muon neutrino and anti-neutrino. This would not be a fast process though and you still need an extremely large detector (thousands of tons or more) to detect them and then there is stil the issue of analysis to get the signal. This makes it impractical for HFT applications although if it could be made to work you'd actually beat the competition by a lot more than a femtosecond: the gain is up to 45 milliseconds if you were transmitting straight through the centre of the Earth.