L. Sperandio

Quantum explorations: from the waltz of the Pauli exclusion principle to the rock of the spontaneous collapse

The spin–statistics connection, in particular the Pauli exclusion principle (PEP), plays a very important role in our comprehension of matter and nature. Presently, the PEP violation, possible within some theories, generates a lively debate; it has given birth to a few experiments looking for tiny effects. The violation of the Pauli exclusion principle experiment put a very strong limit on the PEP violation probability by electrons, using the method of searching for PEP forbidden atomic transitions in a copper target. In this paper we present this experiment, the obtained results and future plans to upgrade the experimental setup with fast silicon drift detectors. We then present the idea of using an analogous experimental technique to search for x-rays as a signature of the spontaneous collapse of the wave function, predicted by the continuous spontaneous localization theories, and some very encouraging preliminary results.

New experimental limit on the Pauli exclusion principle violation by electrons

The Pauli Exclusion Principle (PEP) is one of the basic principles of modern physics and, even if there are no compelling reasons to doubt its validity, it is still debated today because an intuitive, elementary explanation is still missing, and because of its unique stand among the basic symmetries of physics. The present paper reports a new limit on the probability that PEP is violated by electrons, in a search for a shifted K

Testing the Pauli Exclusion Principle for Electrons

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Experimental tests of quantum mechanics: Pauli Exclusion Principle Violation (the VIP experiment) and future perspectives

line in copper: the presence of this line in the soft X-ray copper fluorescence would signal a transition to a ground state already occupied by 2 electrons. The obtained value,

Test of the Pauli Exclusion Principle in the VIP-2 underground experiment

{1/2} beta^{2} leq 4.5times 10^{-28}

Spontaneously Emitted X-rays: An Experimental Signature of the Dynamical Reduction Models

, improves the existing limit by almost two orders of magnitude.

Experimental tests of quantum mechanics – Pauli exclusion principle violation (the VIP experiment) and future perspective

One of the fundamental rules of nature and a pillar in the foundation of quantum theory and thus of modern physics is represented by the Pauli Exclusion Principle. We know that this principle is extremely well fulfilled due to many observations. Numerous experiments were performed to search for tiny violation of this rule in various systems. The experiment VIP at the Gran Sasso underground laboratory is searching for possible small violations of the Pauli Exclusion Principle for electrons leading to forbidden X-ray transitions in copper atoms. VIP is aiming at a test of the Pauli Exclusion Principle for electrons with high accuracy, down to the level of 10−29 – 10−30, thus improving the previous limit by 3–4 orders of magnitude. The experimental method, results obtained so far and new developments within VIP2 (follow-up experiment at Gran Sasso, in preparation) to further increase the precision by 2 orders of magnitude will be presented.

New experimental limit on the Pauli Exclusion Principle violation by electrons—the VIP experiment

The Pauli exclusion principle (PEP) is one of the basic principles of modern physics. Being at the very basis of our understanding of matter, as many other fundamental principles it spurs, presently, a lively debate on its possible limits, deeply rooted in the very foundations of Quantum Field Theory. Therefore, it is extremely important to test the limits of its validity. Quon theory provides a suitable mathematical framework of possible violation of PEP, where the violation parameter q translates into a probability of violating PEP. Experimentally, setting a bound on PEP violation means confining the violation parameter to a value very close to either 1 (for bosons) or -1 (for fermions). The VIP (VIolation of the Pauli exclusion principle) experiment established a limit on the probability that PEP is violated by electrons, using the method of searching for PEP forbidden atomic transitions in copper. We describe the experimental method, the obtained results, both in terms of the q-parameter from quon theory and as probability of PEP violation, we briefly discuss them and present future plans to go beyond the actual limit by upgrading the experimental technique using vetoed new spectroscopical fast Silicon Drift Detectors. We also shortly mention the possibility of using a similar experimental technique to search for eventual X-rays, generated in the spontaneous collapse models.

Searches for the violation of Pauli exclusion principle at LNGS in VIP(-2) experiment

The validity of the Pauli exclusion principle—a building block of Quantum Mechanics—is tested for electrons. The VIP (violation of Pauli exclusion principle) and its follow-up VIP-2 experiments at the Laboratori Nazionali del Gran Sasso search for X-rays from copper atomic transitions that are prohibited by the Pauli exclusion principle. The candidate events—if they exist—originate from the transition of a 2 p orbit electron to the ground state which is already occupied by two electrons. The present limit on the probability for Pauli exclusion principle violation for electrons set by the VIP experiment is 4.7 × 10 − 29 . We report a first result from the VIP-2 experiment improving on the VIP limit, which solidifies the final goal of achieving a two orders of magnitude gain in the long run.

Experimental tests of Quantum Mechanics: from Pauli Exclusion Principle Violation to spontaneous collapse models

We present the idea of searching for X-rays as a signature of the mechanism inducing the spontaneous collapse of the wave function. Such a signal is predicted by the continuous spontaneous localization theories, which are solving the “measurement problem” by modifying the Schrödinger equation. We will show some encouraging preliminary results and discuss future plans and strategy.