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Low-Energy Neutrinos Detected In Real Time

Posted by kdawson on from the tell-me-why-the-stars-do-shine dept.

Roland Piquepaille sends us word of first results from the Borexino detector in Italy, where an international team of more than 100 researchers has detected low-energy solar neutrinos for the first time. These results confirm recent "theories about the nature of neutrinos and the inner workings of the sun and other stars." In particular, it's now almost certain that neutrinos oscillate among three types, namely electron, muon, and tau neutrinos. The Borexino detector lies almost a mile underground near L'Aquila, Italy, and it sets new standards in the purity of the materials used in its construction.

9 of 73 comments (clear)

  1. Neutrinos by the_kanzure · · Score: 4, Informative

    * Neutrino
    * History of the neutrinos [from our perspective, mind you]
    * The Ultimate Neutrino Page
    etc. I should go call up my particle physicist body to post up some comments. :)

  2. The paper by Angstroman · · Score: 5, Informative

    For those interested, the paper itself can be found at http://arxiv.org/abs/0708.2251v1. The team is detecting neutrinos from Be 7 at the rate of 47 per day.

  3. Some basic papers by the_kanzure · · Score: 4, Informative
    TASI 2002 lectures on neutrinos [Yuval Grossman] [PDF]:

    We present a pedagogical review of neutrino physics. In the first lecture we describe the theoretical motivation for neutrino masses, and explain how neutrino flavor oscillation experiments can probe neutrino masses. In the second lecture we review the experimental data, and show that it is best explained if neutrinos are massive. In the third lecture we explain what are the theoretical implications of the data, in particular, what are the challenges they impose on models of physics beyond the SM. We give examples of theoretical models that cop e with some of these challenges.
    Neutrino physics [Evgeny Khakimovich Akhmedov] [PDF]:

    In the present lectures the following topics are considered: general properties of neutrinos, neutrino mass phenomenology (Dirac and Majorana masses), neutrino masses in the simplest extensions of the standard model (including the seesaw mechanism), neutrino oscillations in vacuum, neutrino oscillations in matter (the MSW effect) in 2- and 3-flavour schemes, implications of CP, T and CPT symmetries for neutrino oscillations, double beta decay, solar neutrino oscillations and the solar neutrino problem, and atmospheric neutrinos. We also give a short overview of the results of the accelerator and reactor neutrino experiments and of future projects. Finally, we discuss how the available experimental data on neutrino masses and lepton mixing can be summarized in the phenomenologically allowed forms of the neutrino mass matrix.
    BTW, particle physics has an awesome WWW presence.
  4. Gran Sasso by xPsi · · Score: 5, Informative

    Borexino is really an amazing detector, but has a complex history. The experiment is located at an impressive place called the Gran Sasso National Laboratory (LNGS) in Italy. Technically, it is one of the deepest labs in the world as measured by overburdon -- i.e. it has about a kilometer of rock in every direction to shield cosmic rays-- but is actually located high up in the mountains. Interestingly, it is almost directly under where Mussolini was held prisoner and subsequently rescued by German commandos at Campo Imperatore in 1943. It is also near where the movie Ladyhawke was filmed. Anyway, back in 2002 there was a chemical accident when some of the liquid scintillator material (highly toxic) got into the local ground water. The leak was an honest mistake and was actually rather minor as chemical spills go, but it caused a public relations debacle which tangled up the lab and, in particular, Borexino, in a long bureaucratic nightmare. I'm happy to see they are now back in the game producing cutting-edge results.

    --
    i\hbar\dot{\psi}=\hat{H}\psi
  5. Re:Oops! My bad! by aicrules · · Score: 4, Informative

    Not so fast! Try taking a drink from the firehose on this one. You'll see that while the main link is still there, he DID include a link back to ZDnet that got edited out!

  6. Re:Neutrinos massless = timeless, but change state by Anonymous Coward · · Score: 3, Informative

    You have correctly stated the problem, and the solution is that they must have some mass. There are several experiments underway to measure what their masses are. They are very tiny, probably sub-eV (for reference, the electron has mass of 511,000 eV. and the proton has mass 938,000,000 eV).

  7. Re:Neutrinos massless = timeless, but change state by Angstroman · · Score: 5, Informative

    Indeed, the presumed oscillations imply that the mass of the neutrino is small, but not zero. See, for example http://focus.aps.org/story/v2/st10 for a good discussion. Getting a good experimental measure of the mass of a particle that interacts so weakly with detectors has been a very long running challenge in experimental physics.

  8. Re:Totally gnarly! by Anonymous Coward · · Score: 1, Informative

    His submissions range from deceptive and misleading to plain old wild speculation. This seems to be a first for him, a story that is straightforward, belongs on slashdot and doesn't link back to his blog. It should really be tagged 'bravoroland' or 'abouttimepipsqueak'.

  9. Re:Low-Latency, Direct Communications by Anonymous Coward · · Score: 1, Informative

    Well, problem is... look at what's needed to detect 'em: a HUGE detector mass! (huge amount of target matter).

    I'm afraid that will definitely rule out portable devices... 8-)