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Photon's antiparticle

  1. Feb 3, 2012 #1
    Photon's antiparticle!!!

    It's said that photon is an antiparticle of itself. Also there are some particle following this property. How is this happening?
     
  2. jcsd
  3. Feb 3, 2012 #2

    Pengwuino

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    Re: Photon's antiparticle!!!

    Who says everything has to have a separate, distinguishable anti-particle? There is no reason to assume such a thing must happen. I don't know any other particles that are their own anti-particles (although there are theories that neutrinos may be their own anti-particles but this has not been experimentally shown and is not currently an accepted idea).
     
  4. Feb 3, 2012 #3

    tom.stoer

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    Re: Photon's antiparticle!!!

    the neutral pion π° is its own antiparticle
     
  5. Feb 3, 2012 #4
    Re: Photon's antiparticle!!!

    i heard that force carrier's have this property.
     
  6. Feb 3, 2012 #5

    jtbell

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    Re: Photon's antiparticle!!!

    Not all of them. The W+ and W- are antiparticles.
     
  7. Feb 4, 2012 #6
    Re: Photon's antiparticle!!!

    A particle that is it's own anti-particle is called a Majorana particle (and is elementary). (http://en.wikipedia.org/wiki/Majorana_particle)

    Currently, only Majorana bosons are known to exist, although, the neutrino might be a Majorana fermion.
     
  8. Feb 4, 2012 #7

    clem

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    Re: Photon's antiparticle!!!

    I have never seen (until now) the term 'Majorana bosons' used, because the Majorana equation applies only to fermions.
     
  9. Feb 5, 2012 #8
    Re: Photon's antiparticle!!!

    The photon can not be as it does not self-couple
     
  10. Feb 5, 2012 #9

    tom.stoer

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    Re: Photon's antiparticle!!!

    For the classicfication of particles and antiparticles in terms of C, P- and T-symmetry this is irrelevant
     
  11. Feb 6, 2012 #10
    Re: Photon's antiparticle!!!

    after all what is this c,p,t symmetry means?
     
  12. Feb 7, 2012 #11

    tom.stoer

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    Re: Photon's antiparticle!!!

    C = Charge conjugation
    P = Parity (space inversion)
    T = Time inversion

    You need them to classify particles and antiparticles mathematically
     
  13. Feb 7, 2012 #12
    Re: Photon's antiparticle!!!

    Hi,

    The Z boson and gluon are also there own antiparticle, right?

    Ofir
     
  14. Feb 7, 2012 #13

    clem

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    Re: Photon's antiparticle!!!

    No. A gluon has a color combination, such Red-AntiBlue. Its antiparticle would be
    AntiRed-Blue. The Z is its own antiparticle.
     
  15. Feb 7, 2012 #14
    Re: Photon's antiparticle!!!

    Hi,

    Thanks for your reply

    I agree that a gluon with a specific color combination could have an antiparticle with a different color. However, the resulting color would be a linear combination of the colors of the gluons, with no need for antigluons. I believe that the gluon, as a color octet, is its own antiparticle.

    For example, in supersymmetry, there is a hypothetical particle called the gluino. It has the same charges as the gluon but is spin half. It is treated as a majorana fermion, therefore its own antiparticle.

    Ofir
     
  16. Feb 7, 2012 #15
    Re: Photon's antiparticle!!!

    More than mathematics what is this symmetry?
     
  17. Feb 8, 2012 #16

    tom.stoer

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    Re: Photon's antiparticle!!!

    what do you mean? which symmetry?

    the symmetry of the quarks and gluons is called SU(3); it describes a rotation in a 3-dim. vector complex space; therefore when constructing this SU(3) one finds that there are 8 angles for rotations (instead of 3 as for rotations in a 3-dim. real vector space)
     
  18. Feb 8, 2012 #17
    Re: Photon's antiparticle!!!

    the higgs boson is its own antiparticle.
     
  19. Feb 8, 2012 #18

    tom.stoer

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    Re: Photon's antiparticle!!!

    in the simplest model - and iff it exists ;-)
     
  20. Feb 8, 2012 #19
    Re: Photon's antiparticle!!!

    yes. i just wanted to point out that whenever your field is real, the antiparticle is the same as the particle.
     
    Last edited: Feb 8, 2012
  21. Feb 8, 2012 #20

    tom.stoer

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    Re: Photon's antiparticle!!!

    Good point; this is due to the fact that for a real scalar field the operator C for charge conjugation reduces obviously to the identity, i.e. C=1
     
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