Pion

In particle physics, pion (short for the Greek pi meson = 'P middle') is the collective name for three subatomic particles discovered in 1947: π0, π+ and π−. Pions are the lightest mesons.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Pions have zero spin and are composed of first-generation quarks. In the quark model, an up and an anti-down quark compose a π+, while a down and an anti-up quark compose the π−, its antiparticle. Combinations of up and anti-up, or down and anti-down, would both be neutral, but because they have the same quantum numbers are only found in superpositions. The lowest energy superposition is the π0, which is its own antiparticle.

Particle physics: Particle physics is a branch of physics that studies the elementary constituents of matter and radiation, and the interactions between them. It is also called high energy physics, because many elementary particles do not occur under normal circumstances in nature, but can be created and detected dur...

Greek: The noun Greek refers to:...

Meson: In particle physics, a meson is a strongly interacting boson, that is, it is a hadron with integral spin. In the Standard Model, mesons are composite (non-elementary) particles composed of an even number of quarks and antiquarks. Until the discovery of the tetraquark, all known mesons were believed ...