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Science

A Fermilab First: Detecting Oscillating Neutrinos 43

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.
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A Fermilab First: Detecting Oscillating Neutrinos

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  • by Anonymous Coward

    Thanks for posting

  • by Anonymous Coward on Sunday August 09, 2015 @11:41AM (#50279585)
    Actually, oscillating neutrinos have been detected before. They just were from the sun, not human made. https://en.wikipedia.org/wiki/... [wikipedia.org]
    • by Anonymous Coward

      That's the problem with replicating news from 2nd hand accounts... Fermilab's PR says the detection was the first for the NOvA experiment, which is great because it shows the experiment actually works as expected, but some (if not all) news sites interpreted as if it was a world's first.

    • by Roger W Moore ( 538166 ) on Sunday August 09, 2015 @01:26PM (#50280007) Journal
      Actually the summary is wrong. Neutrino oscillations have been detected before from atmospheric neutrinos, solar neutrinos and beam neutrinos (e.g. the T2K experiment [t2k-experiment.org]). 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!
    • Actually, oscillating neutrinos have been detected before. They just were from the sun, not human made.
      https://en.wikipedia.org/wiki/... [wikipedia.org]

      I was disappointed mass less neutrinos that oscillate, not so mass less. Now I'm reading almost mass less. This is an area one has to keep up with daily or be left behind.

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

      Yes, I was wondering about that--I remember a physics prof saying that all particles oscillated at an integer multiple of Planck's constant, and I knew we'd detected neutrinos before.

      IIRC it's how we detect a supernova before we see the fireball--the neutrinos are so small and move so fast that they make it out of the core of the exploding star a short time before the star actually explodes, giving us a chance to train an instrument or two on the star.

      Astrophysicists in the room, feel free to correct me.

      • by Trax3001BBS ( 2368736 ) on Sunday August 09, 2015 @06:58PM (#50281535) Homepage Journal

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

        IIRC it's how we detect a supernova before we see the fireball--the neutrinos are so small and move so fast that they make it out of the core of the exploding star a short time before the star actually explodes, giving us a chance to train an instrument or two on the star.

        Astrophysicists in the room, feel free to correct me.

        Yes, had detectors all set up waiting for a hit when super nova 1987 came our way, proof positive of neutrinos and their production. https://en.wikipedia.org/wiki/... [wikipedia.org]

        1987a was only seen in the Southern Hemisphere, was said the astronomer who saw it through telescope did a very odd thing, went outside to look at it :) .

      • by Anonymous Coward

        I remember a physics prof saying that all particles oscillated at an integer multiple of Planck's constant, and I knew we'd detected neutrinos before.

        Neutrino oscillations have almost nothing to do with what you're talking about here. What you're talking about is how particles can be described by wavefunctions, which include some wave-like properties and things like integer number of waves fitting into a given space. That has to do with basic things like where you find a particle in a given state. Neutrino oscillations has to do with neutrinos oscillating between each of the different kind of neutrino, basically changing particle as they travel.

  • In what way(s) is this experiment different from https://en.wikipedia.org/wiki/... [wikipedia.org]
    ?
    • by Anonymous Coward

      It is kind of right in the summaries... that one was looking for muon neutrinos oscillating into tau neutrinos, while this one is looking for oscillating into electron neutrinos. Neutrino mixing can be characterized by a four numbers, and measuring the oscillations in different ways can pin down different ones.

    • Notice the eagerness with which former wikipedians [google.com] suggest that the solar neutrino deficit problem has already been solved, even though those claims were only based upon an observation at one end of the path:

      Several neutrino observatories were built in the 1980s to measure the solar neutrino flux as accurately as possible, including the Sudbury Neutrino Observatory and Kamiokande. Results from these observatories eventually led to the discovery that neutrinos have a very small rest mass and do indeed oscill

  • by Anonymous Coward

    The poster has misread the announcement and failed to check his facts. It is the first recorded detection of neutrino oscillation by the equipment of FNAL, not the first detection at all.

  • Can those neutrino oscillations be modulated at will so as to transfer data? Just imagine being the guy with the neutrino path through the Earth's crust beating all those other HFT guys to the femtosecond.

    • by Roger W Moore ( 538166 ) on Sunday August 09, 2015 @01:43PM (#50280069) Journal

      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 [wikipedia.org]). 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.

  • by Anonymous Coward

    Okay, headline and summary are just plain wrong. Neutrino oscillations of nearly all kinds have been observed in countless experiments around the world. This includes man-made neutrinos from accelerators (one example is the famous Opera experiment, which is better known for its false measurement of superluminous neutrino speeds).
    So I really don't understand what the big deal is. I mean, it's nice that NOvA could *also* confirm that neutrinos oscillate, but that's hardly worth a message. Every few months som

    • by Anonymous Coward

      Update: after careful thinking I guess what the article wanted to say is: the NOvA experiment started taking data and accumulated enough statistics to be able to begin some useful analysis.

  • Still love this one. Bar tender looks up and says "Hey we don't serve faster than light neutrinos here!" A neutrino walks into a bar.

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