Fundamental interaction The gravitational force is attributed to the curvature of spacetime, described by Einstein's general theory of relativity. The other three are discrete quantum fields, and their interactions are mediated by elementary particles described by the Standard Model of particle physics. Within the Standard Model, the strong interaction is carried by a particle called the gluon, and is responsible for quarks binding together to form hadrons, such as protons and neutrons. As a residual effect, it creates the nuclear force that binds the latter particles to form atomic nuclei. The weak interaction is carried by particles called W and Z bosons,
Superpartner Superpartner In particle physics, a superpartner (also sparticle) is a class of hypothetical elementary particles. Supersymmetry is one of the synergistic theories in current high-energy physics that predicts the existence of these "shadow" particles. When considering extensions of the Standard Model, the "s-" prefix from "sparticle" is used to form names of superpartners of the Standard Model fermions (sfermions), e.g. the stop squark. The superpartners of Standard Model bosons have an "-ino" (bosinos) appended to their name, e.g. gluino, the set of all gauge superpartners are called the gauginos. According to the supersymmetry theory, each fermion should have a partner