Purely electro-magnetically before a proton (+) and an anti-proton (-) annihilate each other /assume they do/, they form a dipole. What happens after that? In other words, what does an external observer detect - a sudden disturbance of the dipole field or some continuous change from a dipole-field to a monotone vacuum background?

  • 1
    $\begingroup$ Proton-antiproton annihilation is a messy business that generally results in a mix of photons and mesons. That's because the proton is a composite particle. It would be clearer to consider an electron-positron annihilation since that goes cleanly (at low energies) to two photons. It's an interesting question and I don't know the answer. $\endgroup$ – John Rennie Oct 16 '15 at 15:21

The proton and the antiproton are in a quantum mechanical framework,not in a classical one with dipoles and antennas. In the quantum framework the interactions of particles are governed by the solution of quantum mechanical equations which will give the probabilities for the annihilation taking place, and for the appearance of new particles. The necessary integrals are shown in the Feyman diagrams where strict rules apply transferring line to functions and integrals.

antiproton proton

Here is one possibility of what happens when proton annihilates on an antiproton at high energies. A top antitop pair can be produced through the strong interaction.

An equivalent diagram exists where the exchange is a photon. Due to the much smaller coupling constant of the electromagnetic interaction that you require the probability of this happening is very small with respect to the strong annihilation, and this holds true from low energies to higher.

There exist experimental limits for the reaction antiproton proton annihilating to e+e-.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.