#PAULI EXCLUSION PRINCIPLE D FULL#
#PAULI EXCLUSION PRINCIPLE D VERIFICATION#

Without a self-consistent theory, even phenomenologically, to describe a small violation of PEP, a comparison of the limits of the violation probability out of a thorough review of the experimental context can be misleading and controversial. Interpretations of the results from different types of measurement can be model-dependent. In this framework (as discussed by Okun in his 1989 review paper ) there can be only two kinds of experiments: searches for non-Paulian atoms and nuclei, or searches for anomalous electromagnetic transitions.

When this happens, and the fermion system is not in its ground state, we should be able to observe fast electromagnetic transitions with the emission of light quanta. If these states exist, β 2/2 can be interpreted as the probability of having the wrong symmetry fermions meet. In the absence of a complete relativistic theory, the only alternative view compatible with Quantum Mechanics is that there exist rare states of wrong symmetry, as discussed by Rahal and Campa.

#PAULI EXCLUSION PRINCIPLE D FULL#

First introduced by Ignatiev and Kuzmin in a model to accommodate a fermionic state with multi-particle occupancy, the β parameter stayed, although the model turned out to be impossible to extend into a full relativistic QFT, and a self-consistent theoretical framework is still missing, as reviewed by Okun and by Greenberg. The probability of a small violation is represented conventionally in the form of a small violation probability β 2/2 parameter. If we assume as did Ramberg and Snow, that the “new” electrons injected by the external current source have no prior established symmetry with the electrons inside the copper atoms, the detection of the energy-shifted X-rays is an explicit indication of the violation of spin-statistics, and thus of the violation of the PEP for electrons. They can be distinguished in precision spectroscopic measurements using silicon detectors with typical full width half maximum (FWHM) energy resolution less than 200 eV at 8 keV. Because of the shielding effect of the additional electron in the ground level, the energy of such abnormal transitions deviates from the copper K α X-ray at 8 keV by about 300 eV, as shown in the “Appendix”. In particular, they searched for PEP-violating transitions from the 2 p level to the 1 s level of the copper atoms, which is already occupied by two electrons. In the experiment they injected a high electric DC current in a copper conductor, and they searched for X-rays from transitions that are PEP-forbidden after electrons are captured by copper atoms.

This means that transitions between different symmetry states can only be searched in open systems, and the prototype experiment of this class has been first carried out several years ago by Ramberg and Snow.

Particle identity – and therefore the necessity of Hamiltonians that are symmetric with respect to particle exchange – rules out any violation of PEP in closed systems, where the Messiah–Greenberg superselection rule holds (no transitions allowed between states with different symmetry). Exhaustive reviews of the experimental and theoretical searches for a small violation of PEP can be found in. In principle, violations of PEP can be large, e.g., where there are macroscopic violations of statistics of bosons and fermions, or small, if particles violate PEP “only a little”.

#PAULI EXCLUSION PRINCIPLE D VERIFICATION#

However, QFT is not complete and current proofs of the spin-statistics connection may possibly break in extensions of QFT, paving the way to the need of experimental verification of such important results of the theory like the spin-statistics connection and PEP. The principle is extremely robust, and its validity within QFT is unchallenged (see, e.g., ).

Nowadays the spin-statistics connection – on which PEP is based – is one of the basic results of Quantum Field Theory (QFT), and PEP stands as one of the great cornerstones of physics. The Pauli exclusion principle (PEP) explains in a beautiful and elegant way the stability of atoms and a host of other phenomena, but when it was first stated by Pauli in 1924 it was met with skepticism by Bohr and Heisenberg, and Pauli himself thought that his own construction – which included electron spin as well as the exclusion principle – could not easily find support in common sense.

Pauli exclusion principle d