Ph.D (Panjab University)
M.Sc. (Panjab University)
Quantum Chromodynamics views hadrons as bound states of quarks and gluons. As hadrons are made up of quarks and antiquarks, therefore, all aspects of hadronic physics is supposed to be explained through Quantum Chromodynamics. However, hadron structure studies involve non-perturbative aspects of Quantum Chromodynamics- confinement and chiral symmetry breaking which makes it a challenging task to understand. Considerable progress has been achieved through Non-Relativistic Quark Model which is based on very simple assumptions and gives a remarkable fit to many of the hadron spectroscopy data. However, starting with the observations in 1988 by the European Muon Collaboration, in the last decade or so extremely important information pertaining to spin and flavor structure of the proton have been discovered in the deep inelastic scattering experiments. The present experimental information is in contradiction with the predictions of Non-Relativistic Quark Model which referred to as "proton spin problem".