How much energy is released when matter interacts with antimatter?

How much energy is released when matter interacts with antimatter?

Say one proton interacting with an anti proton?

If in an absolute vaccum would antimatter exist for a long time? What causes it to vanish?

The interaction between matter and antimatter produces energy in the
form of radiation, that is equal with the energy of the two initial particles.

You can calculate a particle energy from the equation : E = m * c^2,
where the m is the mass of the particle when it is still, and E=rest energy

Say you have an electron and a positron. Each of them has rest energy 0.51 MeV.
Their interaction would give a photon that has energy 2*0.51 MeV= 1.02 MeV
You can do the same for any other particle-antiparticle couple.

Theoretically, if there is nothing to interact with, antimatter could exist forever.
Absolute vacuum is a theoretical concept though. It can’t be created in lab and
neither be observed in some experimental way as the observation itself
contains at least electromagnetic waves.
So the answer is based on theory and not experiment.
You can read an interesting theory, called "Dirac sea", on the creation of
matter-antimatter in absolute vacuum.

2 Responses to “How much energy is released when matter interacts with antimatter?”

  1. jean-de-la-lune on March 28th, 2010 at 3:14 am

    1/ Energy is conserved, so the energy released is the sum of the energies of the initial proton and antiproton in whichever frame you decide to evaluate them. They can react without annihilating each other, producing other particles (mainly pions) thanks to their kinetic energy and perhaps transforming into neutron and/or antineutron (protons and neutrons transform rapidly into each other by the absorption/emission of pions). Or they can disappear as baryons (=proton, neutron, their ‘anti’s’ and lots of heavier unstable particles) and leave only pions behind. That’s ‘real’ annihilation. Pions themselves decay into leptons and photons, so that there remains no nuclear matter (antimatter) in the end.

    2/ antimatter would of course persist in a vacuum. It does not vanish by itself but only in annihilating with matter.
    References :

  2. The interaction between matter and antimatter produces energy in the
    form of radiation, that is equal with the energy of the two initial particles.

    You can calculate a particle energy from the equation : E = m * c^2,
    where the m is the mass of the particle when it is still, and E=rest energy

    Say you have an electron and a positron. Each of them has rest energy 0.51 MeV.
    Their interaction would give a photon that has energy 2*0.51 MeV= 1.02 MeV
    You can do the same for any other particle-antiparticle couple.

    Theoretically, if there is nothing to interact with, antimatter could exist forever.
    Absolute vacuum is a theoretical concept though. It can’t be created in lab and
    neither be observed in some experimental way as the observation itself
    contains at least electromagnetic waves.
    So the answer is based on theory and not experiment.
    You can read an interesting theory, called "Dirac sea", on the creation of
    matter-antimatter in absolute vacuum.
    References :

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