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Can we really call it an antineutrino?

  1. Jun 11, 2012 #1
    an electron can have a spin +1/2 or -1/2. A positron is identical to an electron except that it has a positive charge. Hence it is the electron's antiparticle.

    A neutrino has a spin of +1/2 while an antineutrino has a spin pf -1/2. I think that we should stop using the term antineutrino. Because the neutrino is its own antiparticle.
     
  2. jcsd
  3. Jun 11, 2012 #2

    Simon Bridge

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    Good luck with that one.

    Note: a positron is an anti-electron because they are complimentary solutions to the Dirac equations ... thus they are "Dirac Fermions". An electron and positron will annihilate. The status of a neutrino is not settled ifaik. If a neutrino were it's own anti-particle then neutrinoless double beta decay should be possible. Do you know of an experiment that shows this? OTOH: I don't know that anyone has demonstrated annihilation of a neutrino and an anti-neutrino.
     
  4. Jun 11, 2012 #3
    I think there were some experimental results suggesting double beta decay at Fermilab.
     
  5. Jun 11, 2012 #4

    Simon Bridge

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    erm - I heard there was a discrepancy between neutrino and anti-neutrino masses which looks like going away with more measurements but not seen double-beta decay. There are a bunch of labs trying for it for a while and nobody seems to have one.

    You got a citation?

    Anyway - you should have said that as evidence in post #1 instead of going on about electrons and positrons.
     
  6. Jun 11, 2012 #5
    I'm not entirely sure about the spin part. If I understand spin correctly you can take spin projection wrt an arbitrary axis so you can turn +1/2 particle into -1/2 particle just by flipping the axis. Or you are referring to the helicity and that is frame dependent for massive particles so you can turn a +1/2 particle into -1/2 particle by Lorentz boost.

    I'm not really sure about this so if someone could clear this it would be much appreciated.
     
  7. Jun 11, 2012 #6

    Vanadium 50

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    First, this is not known to be true. It might be. It might not be.

    Second, do you have any idea how arrogant you sound? "I've read some popularizations, so I know better than the professionals who have been working on this for decades what is correct and what is not." You might want to dial it back a couple notches.
     
  8. Jun 13, 2012 #7
    I've read some popularizations, so I know better than the professionals who have been working on this for decades what is correct and what is not.

    YOU might want to dial it back a couple notches.










    In fact I didn't even read any popularizations, I think I just pulled this crap outta my butt. I oughta be smacked.
     
  9. Jun 14, 2012 #8

    Simon Bridge

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    Back to our regular programming.... arrogance is something of a occupational hazard for physicists.

    I think that we should stop using the term antineutrino. - is an opinion, inherently arrogant, and invites the response "you are allowed to think what you like" or "so what?" You do try to support this opinion with some facts, but you don't support the facts empirically (that citation I asked for would have been a good start). BTW: I had to suppress my initial reaction to this - you get a thick skin after a while but sometimes it gets a bit much. It's usually better just to ignore the arrogant bits - they tend to go away in the ensuing discussion. Besides, there is a faint chance it may be justified. I focussed on answering the question.

    But you didn't ask a question. Answering questions is kinda what we do here so you must be implying a question in there someplace. The implicit question, here is likely something like: "is this opinion well founded?" The answer to this implicit question is "no".

    The stated observations are reasons to consider the possibility but not good enough to draw conclusions. The evidence is still coming in. Look how long it took to work out that neutrinos had mass... this is not going to be resolved in a hurry. [When I was a senior undergrad, neutrinos were massless - but we were aware of experiments being performed to check. Next year, as a post grad, the matter was decided and I had the heady experience of taking a pen to my text-books and editing them. An arrogant move: what? I know better than the authors? Well ... yes. It was a justified arrogance.]

    One of the things we do here is to try work out how someone expressing a poorly founded opinion could have arrived at it and/or could avoid that reasoning in future. In your case, you needed to take into account that none of the large numbers of extremely smart people working on the problem have considered the facts in question compelling though they are certainly aware of them. i.e. the arrogance in the phrasing may have hidden more constructive reasoning.

    If you take this into account when you write the question, you'd end up with different wording - probably along the lines: how is it that the neutrino=majorana fermion question is still considered open given the following facts...? OR considering that this is an undecided question, why default to the neutrino/antineutrino description and not the majorana one?

    See the difference?
    In fact, from questions like that you can usually find your own answers.
    Though it can still be fun discussing them.
     
  10. Jun 16, 2012 #9
    you seem to invest a lot in PF. Though i did create the thread in a hurry.
     
  11. Jun 19, 2012 #10

    Simon Bridge

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    When we articulate underlying reasoning/assumptions, it tends to up the verbiage.
     
  12. Jun 19, 2012 #11

    micromass

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    The OP doesn't seem to be interested in learning, only in arguing. Therefore, the thread is locked.
     
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