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Curiosity for existence of Anti- photons?

  1. Mar 2, 2015 #1
    Hello friends! I am a newbie here. I love quantum physics very much........ especially the standard model of fundamental particles, QED, QCD, etc. I have an urge to create my own theory on space quanta (that's for another time.......) but my main question is:
    • Does anti-particle of a photon exist (i.e. anti-photon) ?
    • And if it does exist then what will be the anhilation product of it? (i.e. photon + anti-photon ---> ???)
    • Also will anti photon help to create black light? (i.e. will it help to create darkness?)
  2. jcsd
  3. Mar 2, 2015 #2


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    The anti-particle of a photon is a photon.

    Photon-photon collisions are very rare. A priori you can create anything as long as conservation laws are obeyed and you have enough energy.

  4. Mar 2, 2015 #3
    For your third reply sir, i meant can we make a certain region ( say a cubic metre) devoid of light by colliding light photons with their corresponding anti photons? ( just like how sound waves nullify each other when they approach out of phase!)
  5. Mar 2, 2015 #4


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    You mean colliding photons with other photons. As its own antiparticle a photon is never called an antiphoton. To answer your question, yes, the possibility exists, but as Orodruin already said, the cross section is exceedingly low, which means that photons very, very rarely interact with each other in annihilation events. But this is nothing like two waves interacting out of phase. Annihilation events between two photons would create other particles.
  6. Mar 2, 2015 #5
    That's what I was asking.
    Can you tell me what will be those particles?
    Will those particles be neutral, charged or massless, etc. And basically what will govern the formation of a particular type of particle from the collision of photons?
    Does that means light created matter and antimatter then why only matter is existing in our visible universe? And where is the rest of antimatter gone?
    Also what's the proof that this matter which we see is "matter" and not the "anti matter"?
  7. Mar 2, 2015 #6


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    As long as you have enough energy, you can produce almost any type of particle as long as conservation rules are followed. For example, two gamma ray photons can annihilate and produce an electron-positron pair.

    If you can answer that question then you'll win a nobel prize. :wink:

    We have defined the matter we are made out of, which is also the dominant matter in the observable universe, to be 'normal matter' and the anti-particles of this matter to be 'anti-matter'. It's just convention, much like its convention to label electrons as having a negative charge and protons as having positive. It could easily be the reverse, but it wouldn't change anything.
  8. Mar 2, 2015 #7
    This is known as the baryonic asymmetry - as yet, an unanswered question in physics. It has been proposed that massive bosons may have played a role in it, but no sound theories exist as of yet.
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