Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Neutrino's anti-particle

  1. Jun 1, 2017 #1
    If the neutrino has zero charge, can it be its own anti-particle? If they are the same particle, can they annihilate?
    Or are they different particles?
    In addition, I read that annihilation would violate one of the conservation laws of the standard model (leptonic number)... How does this happen?
  2. jcsd
  3. Jun 1, 2017 #2


    User Avatar
    Gold Member

    In some theories yes, the neutrinos are their own antiparticles (see for example Majorana neutrinos). But still you would need right-handed neutrinos and left-handed antineutrinos for that (which could potentially exist but not interact with the weak interactions).

    Yes, they could potentially annihilate and you would have processes like the neutrinoless double-beta decay. Searches for those decays in nuclei that are unstable to double beta decays have not found anything significant (they only set limits).

    Again think of the neutrinoless double beta decay, you would have the production of 2 beta particles out of nowhere (and without neutrinos to account for the lepton number conservation). Your lepton number would go from 0 to (-)2...
  4. Jun 1, 2017 #3


    User Avatar
    2017 Award

    Staff: Mentor

    A neutrino has zero electric charge. Electric charge is not the only quantum number particles have.

    It is possible that they are their own antiparticles, experiments cannot rule out (or confirm) that yet. It would mean neutrinos are Majorana fermions.
    If they are, the lepton numbers as we usually define them are not conserved quantities any more. Neutrinoless double beta decay would become possible, the search for this decay is one of the main methods how this is studied.
  5. Jun 1, 2017 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    This is not correct. Majorana neutrinos do not require the existence of right-handed neutrinos. The most basic example of this being the type-II seesaw model where the Weinberg operator is generated when integrating out a scalar triplet instead of singlet fermions.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Threads - Neutrino's anti particle Date
Neutrino Anti-Particle and Flavor Mass Hierarchy Aug 10, 2015
What exactly are anti-neutrinos? May 5, 2014
Mass of an anti electron neutrino Oct 4, 2013