Electron-positron annihilation primarily emits gamma rays at low energies, while at higher energies, there is a probability of producing muon pairs (muons and anti-muons). The energy of the electron-positron pair must exceed the rest mass energy of the particle-antiparticle pair for muon production to occur. Charge conservation is a fundamental principle in these processes, ensuring that if a charged particle is created, an oppositely charged particle must also be produced. This discussion clarifies the conditions under which different particles are emitted during annihilation events.
PREREQUISITESPhysicists, students of particle physics, and anyone interested in understanding the dynamics of electron-positron annihilation and its implications in high-energy interactions.
zhermes said:It depends on the energy of the electron and positron. If they are low energy, the only things that can be created are photons; at higher energies there is some probability that muon-pairs will be produced, and at even higher energies even more massive particles can be produced.
As soon as the energy of the electron-positron pair exceeds the rest mass energy of a particle-anti-particle pair, I think there is some probability that it will be created.
There are numerous quantities you have to conserve; charge is one of them---which means that if a charged species is created (e.g. a muon, q = -e) another particle will also be created with the opposite charge (e.g. an antimuon, q = +e). Similarly, 'lepton number' needs to be conserved, energy, angular momentum (e.g. spin) etc etc.ravisastry said:If photons are created in annihilation, there won't be electric charge created in photons...but for Muon pairs, we have a positive and a negative muon. How can this be possible ?
zhermes said:There are numerous quantities you have to conserve; charge is one of them---which means that if a charged species is created (e.g. a muon, q = -e) another particle will also be created with the opposite charge (e.g. an antimuon, q = +e). Similarly, 'lepton number' needs to be conserved, energy, angular momentum (e.g. spin) etc etc.
Nope. It's experimentally very well established that only the total charge is conserved.ravisastry said:dont we have charge conservation for that particular charges ? like instead of sum total...how about total no of negative (or positive) charges should remain the same pre & post the event ?