Indistinguishability, the Pauli Principle (Quantum Mechanics)

Victor F. Weisskopf

Inna G Kaplan

The connection between the exclusion principle and the principle of indistinguishability of identical particles in quantum mechanics is discussed. It is shown with the aid of a density matrix defined for states with arbitrary permutation symmetry that the particles are indistinguishable only for one-dimensional representations of the permutation group (symmetrical and antisymmetrycal), and are distinguishable in all the states that are degenerate in the permutations. It is demonstrated by the same token that the exclusion principle follows from the principle of indistinguishability of identical particles and the Pauli theorem on the connection between spin and statistics.

Federico Holik, Juan Pablo Jorge, César Massri

R. D. Amado, Henry Primakoff

Particle identity in quantum mechanics makes it impossible to test the Pauli exclusion principle by looking for "forbidden" x rays or $\ensuremath{\gamma}$ rays. Such experiments do, however, test particle stability. Evidence for the indistinguishability of electrons and nucleons is discussed.NUCLEAR STRUCTURE Particle identity and the Pauli exclusion principle, particle stability.

Yasser Omar

In this article, we discuss the identity and indistinguishability of quantum systems and the consequent need to introduce an extra postulate in Quantum Mechanics to correctly describe situations involving indistinguishable particles. This is, for electrons, the Pauli Exclusion Principle, or in general, the Symmetrization Postulate. Then, we introduce fermions and bosons and the distributions respectively describing their statistical behaviour in indistinguishable situations. Following that, we discuss the spin-statistics connection, as well as alternative statistics and experimental evidence for all these results, including the use of bunching and antibunching of particles emerging from a beam splitter as a signature for some bosonic or fermionic states.

Holger Lyre