One of the fundamental principles of quantum mechanics and modern physics is the Pauli Exclusion Principle (PEP). The most direct consequence is the structure of atoms: the way in which electrons fill the different atomic layers around the nucleus. Without this principle, matter would not exist in the known form. The PEP was formulated by Wolfgang Pauli in 1925, during the tumultuous years of quantum mechanics. A possible violation of PEP could be allowed within the scope of theories beyond the Standard Model. It is therefore very important to be able to perform precision measurements on possible violation of the PEP for each particle type. With the advent of new technologies, such measures have become feasible. VIP (Violation of the Pauli Exclusion Principle) has performed a precision measurement of PEP violation for electrons at the INFN underground Gran Sasso Laboratories. The result obtained, a violation probability limit of around 10-29, is the best in the world for a fundamental particle such as the electron. As from 2016 with VIP2, a substantial improvement of VIP, new measurements will be performed with the aim of gaining another two orders of magnitude in the PEP violation probability limit.


Latest modified: 24 May 2016