Why is there more matter than antimatter?(세상에 물질이 존재하는 이유)

At the moment of the Big Bang, space was filled with energy. In the middest of that, pair production and pair annihilation of matter and antimatter happened everywhere. But then, a question comes into our minds. How come only matter survived, when matter-antimatter pairs were created and destructed as pairs? According to CERN, about one out of a billion particles survived, and they were matter, not antimatter. Scientists today don't know exactly why this happened, but they are trying to figure out the answer by studying symmetry violation of 'oscillating particles' such as mesons that show asymmetry.

 

https://steemit.com/life/@pjheinz/mirror-worlds

There are 5 types of symmetry in physics. C symmetry, or charge symmetry is that a particle and its antiparticle obey the same laws of physics and have same characteristics. P symmetry(parity symmetry) is when a particle and its mirror image particle act the same. Particles with 1/2 different spins are defined as each other's mirror image. In the same way, T symmetry is when the direction of time is opposite, CP symmetry when both C and P symmetry aren't violated, and CPT symmetry is when all three types of symmetry(C, P, T) are true. In the case of weak interaction, every types of symmety exept CPT are known to be violated. CPT symmetry is the only one that cannot be broken in any way.

Scientists are trying to find out what kind of mechanism made matter outnumber antimatter, at the start of the universe. They are finding clues about it from observing special types of mesons: ones that show asymmetry. Asymmetry is the violation of symmetry. Such mesons consist of one charm, strange, or bottom quark and an antiquark, which shouldn't be the antiparticle of which it is bound together as a meson. They decay into both matter and antimatter forms, but the rate isn't equal. This, scientists think, is vaguely how there came to be more matter than antimatter in the world. An example of mesons that scientists are studying is the D meson. a D meson is made up of a charm quark paired with an anti up quark or an anti down quark. The reason scienists are studying mesons is to figure out the mechanism of asymmetry in certain particles. Mesons that are made out of charm quarks(such as D mesons) show less asymmetry than those with strange or bottom quarks. If a different mechanism affects those mesons, it could mean that there might be other particles that violate symmetry, and more data on asymmetry.

 

These oscillating particles go through matter and antimatter few million times per second before they decay. 

Scientists are still working to learn the actual mechanism that made the results 'prefer' one side to the other. I hope the truth be discovered soon, so that we all can know the answer to this curious question.