Standard Model of Particle Physics
The Standard Model of Particle Physics predicts the existence of 17 elementary particles.
Basically they are the “bricks” that make up matter. Fermions are particles that have a quantum property called spin (a kind of quantum angular momentum) of semi – integer modulus (½), being described by the Pauli Exclusion principle . In other words, two fermions at the same energy level cannot have the same quantum numbers or occupy the same position in space at the same time .
The “lighter” (less massive) fermions are called leptons (Greek: “light”), and the heavier ones, such as protons, neutrons and atoms, formed by states of quarks bound by the strong interaction , are called hadrons (Greek for “strong”). Trios of quarks are called baryons (protons and neutrons), and pairs of quarks are called mesons .
Bosons are the particles responsible for the interaction between fermions. Unlike them, these particles have no problem occupying the same place in space at the same time . They have integer spin , have no mass and can have an electrical charge . Bosons are the gluons, photons, W and Z bosons, and the Higgs boson. Each of them is responsible for the mediation of a type of force of nature. Photons, for example, are responsible for electromagnetic interaction. Due to its properties, it is possible for a beam of light to pass through another without any collision between them.
Gluons, in turn, are the mediators of the strong interaction , which holds quarks together, forming mesons and baryons. The W and Z bosons are responsible for the electroweak force , common in beta decays . The Higgs boson, in turn, is the particle responsible for attributing mass to fermions.