System of Identical Particles

Symmetry due to identical particles, its consequences on wave function and use in solving problems, need for proper symmetrization of many-body wave function, properties of pair-exchange and permutation operators, etc. have been discussed. Symmetry or antisymmetry of wave function of a system of identical particles is shown to be a permanent characteristic. Existence of two types of particles (bosons and fermions), symmetrization postulate, spin statistics connection, BE and FD statistics discussed. Need for totally symmetric (for bosons) or totally antisymmetric (for fermions) wave function, Pauli exclusion principle, etc. presented. Example of He-atom and collision of identical spin-s particles are also included.