Yes, it is true, but “I read somewhere” isn’t a good reference. You should usually explicitly state where you read it.DiracPool said:I read somewhere that when, say, an electron and positron annihilate, they create two photons which travel in opposite directions in order to conserve linear momentum. Is this true?
Both energy and momentum must be conserved (as well as charge, spin, etc). So one photon cannot do it.DiracPool said:Do you likewise need two photons to do this? Or, can you do it with one photon provided it has enough energy?
Particle creation and annihilation refer to the processes by which particles are generated and destroyed. In quantum field theory, particles can be created from energy, such as in high-energy collisions, and can annihilate each other, converting their mass back into energy. These processes are governed by the principles of quantum mechanics and special relativity.
In high-energy physics experiments, particle creation occurs when particles are accelerated to very high speeds and then collided with each other. The energy from these collisions can produce new particles. For example, in particle accelerators like the Large Hadron Collider, protons are accelerated and smashed together, resulting in the creation of various particles that are then detected and studied.
Virtual particles are temporary particles that exist during the intermediate stages of particle interactions. They are not directly observable but play a crucial role in mediating forces and interactions between particles. In particle creation and annihilation, virtual particles can facilitate the transformation of energy into particles and vice versa, according to the rules of quantum field theory.
Yes, particles and their corresponding antiparticles can annihilate each other when they come into contact. This annihilation process converts the mass of the particles into energy, often in the form of photons (light particles). For example, when an electron and a positron (its antiparticle) meet, they annihilate and produce gamma-ray photons.
Several conservation laws must be obeyed during particle creation and annihilation. These include the conservation of energy, momentum, charge, and other quantum numbers such as lepton number and baryon number. These laws ensure that the total quantities of these properties remain constant before and after the interaction.