arXiv subjects

J. -P. Egger

Publications and source records attributed to J. -P. Egger.

At least 19 recordsLinked to original sources

arXiv2019

VIP2 in LNGS - Testing the Pauli Exclusion Principle for electrons with high sensitivity

The VIP2 (VIolation of the Pauli Exclusion Principle) experiment at the Gran Sasso underground laboratory (LNGS) is searching for possible violations of standard quantum mechanics predictions in atoms at very high sensitivity. We investigate atomic transitions with precision X-ray spectroscopy in order to test the Pauli Exclusion Principle (PEP) and therefore the related spin-statistics theorem. We will present our experimental method for the search for "anomalous" (i.e. Pauli-forbidden) X-ray transitions in copper atoms, produced by "new" electrons, which could have tiny probability to undergo Pauli-forbidden transition to the ground state already occupied by two electrons. We will describe the VIP2 experimental setup, which is taking data at LNGS presently. The goal of VIP2 is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10$^{-31}$. We will present current experimental results and discuss implications of a possible violation.

quant-ph↗

arXiv2018

Detector setup of the VIP2 Underground Experiment at LNGS

The VIP2 experiment tests the Pauli Exclusion Principle with high sensitivity, by searching for Pauli-forbidden atomic transitions from the 2p to the 1s shell in copper at about 8keV. The transition energy of Pauli-forbidden K X-rays is shifted by about 300 eV with respect to the normal allowed K line. This energy difference can be resolved using Silicon Drift Detectors. The data for this experiment is taken in the Gran Sasso underground laboratory (LNGS), which provides shielding from cosmic radiation. An overview of the detection system of the VIP2 experiment will be given. This includes the Silicon Drift Detectors used as X-ray detectors which provide an energy resolution of around 150 eV at 6 keV and timing information for active shielding. Furthermore, the low maintenance requirement makes them excellent X-ray detectors for the use in an underground laboratory. The VIP2 setup will be discussed which consists of a high current target system and a passive as well as an active shielding system using plastic scintillators read out by Silicon Photomultipliers.

physics.ins-det↗

arXiv2018

Experimental search for the violation of Pauli Exclusion Principle

The VIolation of Pauli exclusion principle -2 experiment, or VIP-2 experiment, at the Laboratori Nazionali del Gran Sasso searches for x-rays from copper atomic transition that are prohibited by the Pauli Exclusion Principle. Candidate direct violation events come from the transition of a $2p$ electron to the ground state that is already occupied by two electrons. From the first data taking campaign in 2016 of VIP-2 experiment, we determined a best upper limit of 3.4 $\times$ 10$^{-29}$ for the probability that such a violation exists. Significant improvement in the control of the experimental systematics was also achieved, although not explicitly reflected in the improved upper limit. By introducing a simultaneous spectral fit of the signal and background data in the analysis, we succeeded in taking into account systematic errors that could not be evaluated previously in this type of measurements.

physics.atom-ph↗

arXiv2017

Test of the Pauli Exclusion Principle in the VIP-2 underground 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 transition that are prohibited by the Pauli Exclusion Principle. The candidate events, if they exist, originate from the transition of a $2p$ 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 $\times$ 10 $^{-29}$. We report a first result from the VIP-2 experiment improving on the VIP limit, that solidifies the final goal to achieve a two order of magnitude gain in the long run.

quant-ph↗

arXiv2017

VIP2 at Gran Sasso - Test of the validity of the spin statistics theorem for electrons with X-ray spectroscopy

In the VIP2 (VIolation of the Pauli Exlusion Principle) experiment at the Gran Sasso underground laboratory (LNGS) we are searching for possible violations of standard quantum mechanics predictions. With high precision we investigate the Pauli Exclusion Principle and the collapse of the wave function (collapse models). We will present our experimental method of searching for possible small violations of the Pauli Exclusion Principle for electrons, via the search for "anomalous" X-ray transitions in copper atoms, produced by "new" electrons (brought inside a copper bar by circulating current) which could have the probability to undergo Pauli-forbidden transition to the ground state (1 s level) already occupied by two electrons. We will describe the concept of the VIP2 experiment taking data at LNGS presently. The goal of VIP2 is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10$^{-31}$. We will show preliminary experimental results obtained at LNGS and discuss implications of a possible violation.

physics.ins-det↗

arXiv2017

Underground test of quantum mechanics - the VIP2 experiment

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, produced by fresh electrons (brought inside the copper bar by circulating current) which can have the probability to undergo Pauli-forbidden transition to the 1 s level already occupied by two electrons and we describe the VIP2 (VIolation of PEP) experiment under data taking at the Gran Sasso underground laboratories. In this paper the new VIP2 setup installed in the Gran Sasso underground laboratory will be presented. The goal of VIP2 is to test the PEP for electrons 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.

quant-ph↗

arXiv2017

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

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.

quant-ph↗

arXiv2016

VIP 2: Experimental tests of the Pauli Exclusion Principle for electrons

The Pauli Exclusion Principle (PEP) was famously discovered in 1925 by the austrian physicist Wolfgang Pauli. Since then, it underwent several experimental tests. Starting in 2006, the VIP (Violation of the Pauli Principle) experiment looked for 2p to 1s X-ray transitions in copper, where 2 electrons are present in the 1s state before the transition happens. These transitions violate the PEP, and the lack of detection of the corresponding X-ray photons lead to a preliminary upper limit for the violation of the PEP of 4.7 * 10^(-29). The follow-up experiment VIP 2 is currently in the testing phase and will be transported to its final destination, the underground laboratory of Gran Sasso in Italy, in autumn 2015. Several improvements compared to its predecessor like the use of new X-ray detectors and active shielding from background gives rise to a goal for the improvement of the upper limit of the probability for the violation of the Pauli Exclusion Principle of 2 orders of magnitude.

physics.ins-det↗

arXiv2016

Application of photon detectors in the VIP2 experiment to test the Pauli Exclusion Principle

The Pauli Exclusion Principle (PEP) was introduced by the austrian physicist Wolfgang Pauli in 1925. Since then, several experiments have checked its validity. From 2006 until 2010, the VIP (VIolation of the Pauli Principle) experiment took data at the LNGS underground laboratory to test the PEP. This experiment looked for electronic 2p to 1s transitions in copper, where 2 electrons are in the 1s state before the transition happens. These transitions violate the PEP. The lack of detection of X-ray photons coming from these transitions resulted in a preliminary upper limit for the violation of the PEP of $4.7 \times 10^{-29}$. Currently, the successor experiment VIP2 is under preparation. The main improvements are, on one side, the use of Silicon Drift Detectors (SDDs) as X-ray photon detectors. On the other side an active shielding is implemented, which consists of plastic scintillator bars read by Silicon Photomultipliers (SiPMs). The employment of these detectors will improve the upper limit for the violation of the PEP by around 2 orders of magnitude.

physics.ins-det↗

arXiv2016

Searches for the Violation of Pauli Exclusion Principle at LNGS in VIP(-2) experiment

The VIP (Violation of Pauli exclusion principle) experiment and its follow-up experiment VIP-2 at the Laboratori Nazionali del Gran Sasso (LNGS) search for X-rays from Cu atomic states that are prohibited by the Pauli Exclusion Principle (PEP). The candidate events, if they exist, will originate from the transition of a $2p$ orbit electron to the ground state which is already occupied by two electrons. The present limit on the probability for PEP violation for electron is 4.7 $\times10^{-29}$ set by the VIP experiment. With upgraded detectors for high precision X-ray spectroscopy, the VIP-2 experiment will improve the sensitivity by two orders of magnitude.

physics.ins-det↗

arXiv2015

High sensitivity tests of the Pauli Exclusion Principle with VIP2

The Pauli Exclusion Principle is one of the most fundamental rules of nature and represents a pillar of modern physics. According to many observations the Pauli Exclusion Principle must be extremely well fulfilled. Nevertheless, numerous experimental investigations were performed to search for a small violation of this principle. The VIP experiment at the Gran Sasso underground laboratory searched for Pauli-forbidden X-ray transitions in copper atoms using the Ramberg-Snow method and obtained the best limit so far. The follow-up experiment VIP2 is designed to reach even higher sensitivity. It aims to improve the limit by VIP by orders of magnitude. The experimental method, comparison of different PEP tests based on different assumptions and the developments for VIP2 are presented.

quant-ph↗

arXiv2014

Testing the Pauli Exclusion Principle for electrons at LNGS

High-precision experiments have been done to test the Pauli exclusion principle (PEP) for electrons by searching for anomalous $K$-series X-rays from a Cu target supplied with electric current. With the highest sensitivity, the VIP (VIolation of Pauli Exclusion Principle) experiment set an upper limit at the level of $10^{-29}$ for the probability that an external electron captured by a Cu atom can make the transition from the 2$p$ state to a 1$s$ state already occupied by two electrons. In a follow-up experiment at Gran Sasso, we aim to increase the sensitivity by two orders of magnitude. We show proofs that the proposed improvement factor is realistic based on the results from recent performance tests of the detectors we did at Laboratori Nazionali di Frascati (LNF).

quant-ph↗

arXiv2013

Testing the Pauli Exclusion Principle for Electrons

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.

nucl-ex↗

arXiv2008

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

The Pauli Exclusion Principle is one of the basic principles of modern physics and is at the very basis of our understanding of matter: thus it is fundamental importance to test the limits of its validity. Here we present the VIP (Violation of the Pauli Exclusion Principle) experiment, where we search for anomalous X-rays emitted by copper atoms in a conductor: any detection of these anomalous X-rays would mark a Pauli-forbidden transition. ] VIP is currently taking data at the Gran Sasso underground laboratories, and its scientific goal is to improve by at least four orders of magnitude the previous limit on the probability of Pauli violating transitions, bringing it into the 10**-29 - 10**-30 region. First experimental results, together with future plans, are presented.

quant-ph↗

arXiv2006

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

The Pauli exclusion principle (PEP) represents one of the basic principles of modern physics and, even if there are no compelling reasons to doubt its validity, it still spurs a lively debate, because an intuitive, elementary explanation is still missing, and because of its unique stand among the basic symmetries of physics. A new limit on the probability that PEP is violated by electrons was estabilished by the VIP (VIolation of the Pauli exclusion principle) Collaboration, using the method of searching for PEP forbidden atomic transitions in copper. The preliminary value, ${1/2}β^{2} \textless 4.5\times 10^{-28}$, represents an improvement of about two orders of magnitude of the previous limit. The goal of VIP is to push this limit at the level of $10^{-30}$.

quant-ph↗

arXiv2006

VIP: An Experiment to Search for a Violation of the Pauli Exclusion Principle

The Pauli Exclusion Principle is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its fundamental standing, it is very important to check it as thoroughly as possible. Here we describe the VIP (VIolation of the Pauli exclusion principle) experiment, an improved version of the Ramberg and Snow experiment (E. Ramberg and G. Snow, {\it Phys. Lett. B} {\bf 238}, 438 (1990)); VIP has just completed the installation at the Gran Sasso underground laboratory, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to $β^2/2 \approx 10^{-30} - 10^{-31}$. We report preliminary experimental results and briefly discuss some of the implications of a possible violation.

quant-ph↗

arXiv2005

The VIP Experiment

The Pauli Exclusion Principle (PEP) is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its importance, it is very important to check it as thoroughly as possible. Here we describe the VIP (Violation of PEP) experiment, an improved version of the Ramberg and Snow experiment (Ramberg and Snow, Phys. Lett. B238 (1990) 438); VIP shall be performed at the Gran Sasso underground laboratories, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to $\frac{β^2}{2} \sim 10^{-30}$

quant-ph↗

arXiv2003

Muon transfer from deuterium to helium

We report on an experiment at the Paul Scherrer Institute, Villigen, Switzerland measuring x rays from muon transfer from deuterium to helium. Both the ground state transfer via the exotic dmu3,4He* molecules and the excited state transfer from mud* were measured. The use of CCD detectors allowed x rays from 1.5 keV to 11 keV to be detected with sufficient energy resolution to separate the transitions to different final states in both deuterium and helium. The x-ray peaks of the dmu3He* and dmu4He* molecules were measured with good statistics. For the D2+3He mixture, the peak has its maximum at E_dmu3He = 6768 +- 12 eV with FWHM Gamma_dmu3He = 863 +- 10 eV. Furthermore the radiative branching ratio was found to be kappa_dmu3He = 0.301 +- 0.061. For the D_2+4He mixture, the maximum of the peak lies at E_dmu4He = 6831 +- 8 eV and the FWHM is Gamma_dmu4He = 856 +- 10 eV. The radiative branching ratio is kappa_dmu4He = 0.636 +- 0.097. The excited state transfer is limited by the probability to reach the deuterium ground state, q_1s. This coefficient was determined for both mixtures: q^3He_1s = 68.9 +- 2.7% and q^4He_1s = 90.1 +- 1.5.

nucl-ex↗