Final answer:
Particles are grouped into leptons, hadrons, and gauge bosons. Baryons and mesons, subsets of hadrons, are subject to baryon number and charge conservation, while leptons have associated lepton numbers. Conservation laws govern particle interactions and decays.
Step-by-step explanation:
Particles are categorized into three main groups: leptons, hadrons, and carrier particles (gauge bosons). Leptons are particles that do not interact via the strong nuclear force, while hadrons, which include baryons and mesons, do interact via the strong force. Each of these particles is associated with specific quantum numbers: charge, baryon number, and lepton number.
Baryons, such as protons and neutrons, are composed of three quarks and have a baryon number of 1 for particles and -1 for antiparticles. They have integral charges, with the proton having a charge of +1 and the neutron having a charge of 0. Mesons, on the other hand, are made up of a quark-antiquark pair and have a baryon number of 0, with integral charge values as well. Examples include pions (π) with charges of +1, 0, or -1.
Leptons are pointlike particles with no discernible size beyond their wavelength and are felt down to about 10-18 m. They fall into three families: the electron family (Le), muon family (Lu), and tau family (Lt), each with a corresponding lepton number. Examples include electrons, muons, and tau particles, plus their associated neutrinos.
Overall, particles must obey certain conservation laws including conservation of charge, baryon number, and lepton number, which are pivotal in determining the viability of particle interactions or decays.