There isn't one single name for "particle theory" as a whole. It's a broad field encompassing many different theories and models about the fundamental building blocks of matter. However, here are some common terms used to refer to various aspects of particle theory:

* Particle Physics: This is the most general term, encompassing the study of elementary particles and their interactions.

* Quantum Field Theory (QFT): This is a theoretical framework used to describe the behavior of particles and forces. It forms the foundation for many particle physics models.

* Standard Model: This is a specific theory within particle physics that describes the fundamental particles and forces known to exist.

* String Theory: This is a theoretical framework that attempts to unify all forces of nature by proposing that fundamental particles are actually one-dimensional strings vibrating at different frequencies.

* Quantum Chromodynamics (QCD): This is a theory that describes the strong force, which binds quarks together to form protons and neutrons.

* Electroweak Theory: This is a theory that unifies the electromagnetic and weak forces.

So, the best answer depends on what specific aspect of particle theory you're interested in.