What Feynman diagrams represent — visual shorthand for terms in perturbative quantum field theory calculations

Which Feynman diagrams represent the visual shorthand for terms in non-abelian gauge theory calculations in the context of quantum chromodynamics (QCD)?

Feynman diagrams for non-abelian gauge theory: gluon lines with self-interactions

What QCD (quantum chromodynamics) describes — the strong force between quarks mediated by gluons

QCD describes the strong force interactions between quarks via gluon exchange

What the path integral formulation does — Feynman showed a particle takes all possible paths simultaneously

Path integral formulation: Particle simultaneously explores all paths, summing probabilities

What the renormalization group does — explains how physics changes with the scale of observation

Renormalization group describes scale-dependent behavior in physical systems

How many types of fundamental forces are represented in the Standard Model of particle physics and which gauge bosons mediate each of these forces?

Four fundamental forces: electromagnetic (photon), weak (W and Z bosons), strong (gluons), gravity (graviton, not yet confirmed)

What the Higgs field does — permeates all space, gives mass to fundamental particles through coupling

The Higgs field permeates space, endowing particles with mass via interaction