Physics XII Content
Quark is an elementary particle which interacts through strong nuclear force. There are six quarks (or called flavors of quarks) which are grouped into 3 pairs, up and down, charmed and strangles and top & bottom. These fundamental particles form neutrons, protons, etc. which are collectively known as hadrons. the quarks are peculiar as they possess a charge which is a fraction of that electron. Quarks are more massive than Leptons. The detail of quarks is given below:
Leptons are elementary particles which interact thought the electromagnetic, weak and gravitational force but not interact through strong nuclear force. There are 6 leptons in total, each with their anti-lepton counterpart which are given below.
Mesons are intermediate mass particle which are mad e up of quark, anti – quark pairs.
eg: Pions, Kaons and eta
Baryons are massive particles which are made up of three quarks in the standard mode. This class of particles includes the proton and neutron. Baryons are the Lambda, sigma (and omega) particles. (Baryons are distinct from mesons in that mesons are composed of only two quarks) Baryons and mesons are included in the overall class known as hadrons, the particles which interact by the strong force. Baryons are fermions, while masons are bosons. Besides charge and spin (1/2 for baryon), two other quantum numbers are assigned to these particles are baryon number (B=1) and strangeness(s). The conservation of baryon number is an important rule for interaction and decays of baryons.
Particle physics is the study of the fundamental constituents of matter and the forces of nature. Elementary particle physics addresses the question “What is matter made up of ?”