VIP-2 at LNGS: An experiment on the validity of the Pauli Exclusion Principle for electrons

J Márton ,E Widmann,L Sperandio,S Bartalucci,C Berucci,O Vázquez Doce ,S Di Matteo,D Sirghi,A Clozza,C Curceanu,K Piscicchia,A Scordo,J P Egger ,L De Paolis,M Bazzi,Angelo Bassi ,M Bragadireanu,S Bertolucci,M Iliescu,A Pichler,C Guaraldo,D Pietreanu,M Cargnelli,F Sirghi,H Shi,Sandro Donadi ,E Milotti,J Zmeskal,M Laubenstein

doi:10.1088/1742-6596/873/1/012018

Abstract

We are experimentally investigating possible violations of standard quantum mechanics predictions in the Gran Sasso underground laboratory in Italy. We test with high precision the Pauli Exclusion Principle and the collapse of the wave function (collapse models). We present our method of searching for possible small violations of the Pauli Exclusion Principle (PEP) for electrons, through the search for “anomalous” X-ray transitions in copper atoms. These transitions are produced by “new” electrons (brought inside the copper bar by circulating current) which can have the possibility to undergo Pauli-forbidden transition to the 1s level already occupied by two electrons. We describe the VIP2 (VIolation of the Pauli Exclusion Principle) experimental data taking at the Gran Sasso underground laboratories. The goal of VIP2 is to test the PEP for electrons in agreement with the Messiah-Greenberg superselection rule with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10−31. We show preliminary experimental results and discuss implications of a possible violation.

Highlights

IntroductionPublished under licence by IOP Publishing Ltd one of the most important rules of nature and it has many consequences related to the periodic system of the elements and to the stability of matter, the existence/stability of neutron stars and many other phenomena
We present our method of searching for possible small violations of the Pauli Exclusion Principle (PEP) for electrons, through the search for “anomalous” X-ray transitions in copper atoms
We describe the VIP2 (VIolation of the Pauli Exclusion Principle) experimental data taking at the Gran Sasso underground laboratories

Summary

Introduction

Published under licence by IOP Publishing Ltd one of the most important rules of nature and it has many consequences related to the periodic system of the elements and to the stability of matter, the existence/stability of neutron stars and many other phenomena. We know that the Pauli Exclusion Principle (PEP) is itself a consequence of the spin-statistics theorem which divides nature in fermionic and bosonic systems. In spite of all efforts, no simple intuitive explanation for the PEP could be given - but several proofs of the Spin-statistics relation (Pauli exclusion principle) based on complicated arguments can be found in the literature [3, 4]. The proof by Luders and Zumino [4] is based on a clear set of assumptions:

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Conclusion