Does matter and antimatter came from the splitting of a single particle?

Answer 1

Hi Steph_15

Antimatter and matter particle pairs are created whenever there is sufficient energy density around to create them*. Example: An electron has a mass-energy of 0.5MeV (the electron-volt, eV, is a very small unit of energy). A positron (anti-electron) has the same mass energy, therefore we need 1.0MeV of available energy to create this particle pair. Particle pair creation *always* occurs in matter-antimatter pairs. To get this energy we might collide some other particles together, or we might use a high energy field**. However it's not correct to think that the particle collision creates a matter-antimatter pair: what happens is that the collision makes a localised energy density out of which we get particle pair creation.

* Sometimes when there isn't enough energy available you can get spontaneous pair creation anyway - the extra energy is "borrowed" from the quantum vacuum for a short period of time as determined by the uncertainty principle in energy and time.

** Fields carry energy densities. Examples of pair creation in fields include strong e/m fields; the creation of quark pairs at the confinement limit of the gluon field in QCD; the creation of particle pairs in the strongly curved gravitaitonal field near a black hole horizon in the hawking radiation mechanism.


Hope this helps!
The Chicken

Answer 2

Positrons are found in cosmic rays and can be produced on Earth by bombarding ordinary atoms with protons, causing them to break up and emit various particles, including useful bits of antimatter.

Other subatomic forms of antimatter, including antiquarks and antimesons—particles even smaller than protons—have been created in antimatter "factories"