What is particle physics?
Please see below.
Particle physics is the branch of physics that deals with the properties, relationships, and interactions of subatomic particles, which include electrons, protons, and neutrons.
Protons and neutrons are infact made up of quarks, Other particles produced by radiative and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles are also included.
It is also called high energy physics, because many elementary particles do not occur under normal circumstances in nature, but are created and detected during collisions such as in particle accelerators.