Electron–positron annihilation

All processes must satisfy a number of conservation laws, including: As with any two charged objects, electrons and positrons may also interact with each other without annihilating, in general by elastic scattering.

[2] A convenient frame of reference is that in which the system has no net linear momentum before the annihilation; thus, after collision, the gamma photons are emitted in opposite directions.

The same would be true for any other particles, which are as light, as long as they share at least one fundamental interaction with electrons and no conservation laws forbid it.

The driving motivation for constructing the International Linear Collider is to produce the Higgs bosons (mass 125.09 GeV/c2) in this way.

It is also used as a method of measuring the Fermi surface and band structure in metals by a technique called Angular Correlation of Electron Positron Annihilation Radiation.