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A new study, published suggests that the Standard Model of particle physics can potentially explain the matter-antimatter asymmetry in the universe
This research introduces a mechanism that satisfies one of the Sakharov conditions needed to explain why the universe is made of matter, not antimatter.
The study shows that processes involving mesons (quark-antiquark pairs) could help control the matter-antimatter imbalance, potentially solving this mystery.
What is Antimatter
Antimatter consists of antiparticles, which have the same mass as regular particles but opposite electric charge.
Examples: The antiparticle of an electron (antielectron) is positively charged, while the electron itself is negatively charged.
Antimatter exists in small amounts in cosmic rays, and it is produced in tiny quantities in the Earth’s atmosphere (e.g., one antielectron every 20 seconds from potassium-40 decay).
While antimatter exists, the universe mostly consists of matter.
If there had been equal amounts of matter and antimatter after the Big Bang, they would have annihilated each other, leaving behind nothing but radiation.
This "matter-antimatter asymmetry" is still unexplained.
Standard Model of Elementary Particles
It includes particles like quarks, leptons (e.g., electrons), and the force-carrier particles (e.g., photons for electromagnetic force).
A quark is a type of elementary particle and a fundamental constituent of matter.
Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei.
In particle physics, a lepton is an elementary particle of half-integer spin (spin 1/2) that does not undergo strong interactions.
Two main classes of leptons exist: charged leptons (also known as the electron-like leptons or muons), including the electron, muon, and tauon, and neutral leptons, better known as neutrinos.
A boson is a particle whose wave function is symmetric under particle exchange and therefore follows Bose–Einstein statistics.
In particle physics, a gauge boson is a bosonic elementary particle that acts as the force carrier for elementary fermions. All known gauge bosons have a spin of 1
A scalar boson is a boson whose spin equals zero.
The Standard Model predicted that the universe should respect "CP symmetry" (the combination of Charge Conjugation (C) and Parity (P) transformations), but this symmetry is violated in weak force interactions.
Charge conjugation :Switches particles with their antiparticles, changing the sign of all charges.
Parity : Inverts space, or reflects the space coordinates of a particle through the origin.
Experiments in 1964 showed that CP symmetry is violated in certain particle interactions (e.g., mesons decaying), which is critical for explaining the matter-antimatter imbalance.
Sakharov Conditions: These are three key conditions necessary to explain the matter-antimatter asymmetry in the early universe:
(1) Violation of CP symmetry,
(2) Violation of baryon number conservation, and
(3) Out-of-equilibrium interactions.
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