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

## TL;DR

The VIP-2 experiment at LNGS tests the Pauli Exclusion Principle for electrons with unprecedented precision by searching for anomalous X-ray transitions in copper, aiming to detect possible violations predicted by certain quantum models.

## Contribution

This work introduces a highly sensitive experimental method to test PEP violations for electrons, reaching a probability limit of 10E-31, which is more precise than previous tests.

## Key findings

- Preliminary results show no violation detected within the experimental sensitivity.
- The experiment sets new upper limits on PEP violation probability for electrons.
- Implications for quantum mechanics and collapse models are discussed.

## 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 10E-31. We show preliminary experimental results and discuss implications of a possible violation.