B mesons are subatomic particles made up of a bottom quark and either an up or down antiquark. They are part of the family of particles known as mesons, which are composed of a quark and an antiquark. B mesons play a crucial role in the study of particle physics and quantum chromodynamics, helping scientists understand the fundamental forces that govern matter. These particles are particularly interesting because they can oscillate between different states, a phenomenon known as B meson mixing. This behavior allows researchers to investigate CP violation, which is essential for explaining the matter-antimatter asymmetry in the universe.