The Standard Model of Particle Physics is the theory explaining the fundamental constituentsthat make up all particles and interactions of matter. The Standard Model containssix quarks denoted u, d, t, b, s, and c. Quarks cannot be free in nature and so they formtwo-quark groups (mesons) and three-quark groups (baryons) called hadrons. The most stable hadrons are protons (uud) and neutrons (udd). While hadrons are composed ofconstituent quarks, leptons are particles that are unable to be broken down into smaller unitsof matter. The Standard Model has three negatively charged leptons, which are described
ass having lepton flavors called the electron (e), the muon (¿) and the tau (¿). Each of thecharged leptons is accompanied by a neutral lepton partner called the neutrino, denotedby their lepton flavor as ¿e, ¿¿ and ¿¿ . Quarks and leptons have an equivalent antiparticledenoted either by a bar ( ¯ ¿e) in the case of quarks and neutrinos or by a superscript of + referring to the positive charge.