How the antimatter is created?
In high energy collisions antimatter is created. This is mainly in particle colliders and in the upper atmosphere where energetic solar wind hits the particles of the atmosphere and genrate, for example, pions, which are mesons containing an quark and an antiquark. It can also be created in beta decay. When a proton decays to a neutron, positron and an electron-neutrino, the positron is the antiparticle of the electron. The (lone) proton is thought to be stable as it is the lightest baryon, but in the nucleus, strong force potentials can alter effective stabilities. ——————————— EDIT: In the answer below, momentum is not conserved. In the centre of momentum frame of the particle-antiparticle pair, if only one gamma ray resulted from he anihallation event, i would have to have zero velocity so that momentum is conserved. Instead, annihalation and creation events occur involving two photons, so a lone gamma ray will not do this. Another diference is that the particle
