The top quark, also known as the t quark or truth quark, is one of the elementary particles in the Standard Model of particle physics. It is classified as a fermion and belongs to the group of fundamental particles called quarks. The top quark is the most massive of all known elementary particles, with a mass of approximately 173 GeV/c².
The top quark interacts primarily through the strong nuclear force, which is responsible for binding quarks together inside hadrons (composite particles made up of quarks). It carries an electric charge of +2/3e, where e represents the elementary charge. The top quark interacts with other particles via three fundamental forces: the strong nuclear force, the weak nuclear force, and electromagnetism.
Due to its relatively short lifetime, the top quark doesn't have sufficient time to form stable hadrons before it decays. Instead, it undergoes weak decays mediated by the weak force. The most common decay mode for the top quark is into a W boson (a carrier of the weak force) and a bottom quark. This decay occurs nearly 100% of the time for a top quark. The W boson subsequently decays into other particles, such as leptons (such as electrons or muons) and neutrinos.
The top quark can also interact via the exchange of virtual particles, which are particle-antiparticle pairs that spontaneously form and annihilate. These virtual particles include gluons (mediators of the strong force) and photons (mediators of electromagnetism).
Overall, the top quark's interactions and decay processes provide valuable insights into the fundamental forces and particles of the Standard Model and contribute to our understanding of particle physics.