HIGH SENSITIVITY QUANTUM MECHANICS TESTS IN THE COSMIC SILENCE

The VIP experiment aims to perform high-precision tests of the Pauli Exclusion Principle for electrons in the extremely low cosmic background environment of the Underground Gran Sasso Laboratories of INFN (Italy). The experimental technique consists in introducing a DC current in a copper conductor, searching for K α PEP-forbidden atomic transitions when the K shell is already occupied by two electrons. The results of a preliminary data analysis, corresponding to the first run of the VIP-2 data taking (2016–2017), are presented. The experimental setup in the final configuration is described together with preliminary spectra from the 2019 data-taking campaign

High Precision Test of the Pauli Exclusion Principle for Electrons

The VIP-2 experiment aims to perform high precision tests of the Pauli Exclusion Principle for electrons. The method consists in circulating a continuous current in a copper strip, searching for the X radiation emission due to a prohibited transition (from the 2p level to the 1s level of copper when this is already occupied by two electrons). VIP already set the best limit on the PEP violation probability for electrons $\frac{1}{2} \beta^2 < 4.7 \times 10^{-29}$, the goal of the upgraded VIP-2 (VIolation of the Pauli Exclusion Principle-2) experiment is to improve this result of two orders of magnitude at least. The experimental apparatus and the results of the analysis of a first set of collected data will be presented

Search for a remnant violation of the Pauli exclusion principle in a Roman lead target

In this paper we report on the results of two analyses of the data taken with a dedicated VIP-Lead experiment at the Gran Sasso National Laboratory of the INFN. We use measurements taken in an environment that is especially well screened from cosmic rays, with a metal target made of “Roman lead” which is characterised by a low level of intrinsic radioactivity. The analyses lead to an improvement, on the upper bounds of the Pauli Exclusion Principle violation for electrons, which is more than one (four) orders of magnitude, when the electron-atom interactions are described in terms of scatterings (or close encounters) respectively

NEW CONCEPTS IN TESTS OF THE PAULI EXCLUSION PRINCIPLE IN BULK MATTER

The standard scheme of several tests of the Pauli Exclusion Principle in bulk matter — both in the experiment and in the subsequent data analysis — has long been based on the seminal paper by E. Ramberg, G.A. Snow [Phys. Lett. B 238, 438 (1990)]. The ideas exposed in that paper are so simple and immediate that they have long gone unchallenged. However, while some of the underlying approximations are still valid, other parts of the article must be reconsidered. Here, we discuss some new concepts that are related to the motion of the electrons in the test metal (the “target” of the experiment) and which have been recently studied in the framework of the VIP-2 Collaboration

probing strong interaction with siddharta 2

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Energy Response of Silicon Drift Detectors for Kaonic Atom Precision Measurements

Novel, large-area silicon drift detectors (SDDs) have been developed to perform precision measurements of kaonic atom X-ray spectroscopy, for the study the K &macr; N strong interaction in the low-energy regime. These devices have special geometries, field configurations and read-out electronics, resulting in excellent performances in terms of linearity, stability and energy resolution. In this work the SDDs energy response in the energy region between 4000 eV and 12,000 eV is reported, revealing a stable linear response within 1 eV and good energy resolution

Characterization and Analysis of Cross-Talk on Monolithic SDD Arrays for the SIDDHARTA Experiment

This work is mainly focused on characterization and analysis of cross-talk of a detection module for X-ray spectroscopy which is developed for the SIDDHARTA experiment. The SIDDHARTA experiment is designed to investigate strong nuclear interactions using exotic atoms in the field of nuclear physics. Silicon Drift Detectors (SDDs) used in this experiment are arranged in arrays of 2 imes4 elements with total area of 612 mm^2. At the final stage of SIDDHARTA experiment, 48 SDD arrays are needed to be utilized in a gantry structure to perform X-ray spectroscopy of exotic nuclei, like kaonic deuterium. Each single SDD unit in 2 imes4 formation of arrays is coupled to a charge sensitive preamplifier, namely CUBE, which is followed by shaping amplifier, and consequent analog and digital electronics that are all integrated on a custom developed multichannel chip called SFERA. This work aims to study the effect of charge sharing on SDD channels upon absorption of Xrays and background particles on SDD to investigate the performances of such devices when expected to be irradiated with X-rays signals and with a large background due to MIPs of the accelerator

Studies of kaonic atoms at the DAΦNE collider: from SIDDHARTA to SIDDHARTA-2

The DAΦNE electron-positron collider of the Laboratori Nazionali di Frascati of INFN is a worldwide unique low-energy kaon source and for this reason is suitable for low-energy kaon physics like kaonic atoms and kaon-nucleons/nuclei interaction studies. Kaonic atoms are atomic systems where an electron is replaced by a negatively charged kaon, containing the strange quark, which interacts in the lowest orbits with the nucleus also by the strong interaction. As a result, their study offers the unique opportunity to perform experiments equivalent to scattering at vanishing relative energy. This allows to study the strong interaction between the antikaon and the nucleon or the nucleus “at threshold”, without the need of ad hoc extrapolation to zero energy, as in scattering experiments. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium, were carried out by the SIDDHARTA collaboration at the DAΦNE electron-positron collider of LNF-INFN, by combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and precise Silicon-Drift X-ray Detectors. The measurement of kaonic deuterium will be realized in the near future by SIDDHARTA-2, a major upgrade of SIDDHARTA

X-ray Detectors for Kaonic Atoms Research at DAΦNE

This article presents the kaonic atom studies performed at the INFN National Laboratory of Frascati (Laboratori Nazionali di Frascati dell&#8217;INFN, LNF-INFN) since the opening of this field of research at the DA &#934; NE collider in early 2000. Significant achievements have been obtained by the DA &#934; NE Exotic Atom Research (DEAR) and Silicon Drift Detector for Hadronic Atom Research by Timing Applications (SIDDHARTA) experiments on kaonic hydrogen, which have required the development of novel X-ray detectors. The 2019 installation of the new SIDDHARTA-2 experiment to measure kaonic deuterium for the first time has been made possible by further technological advances in X-ray detection

Kaonic Atoms to Investigate Global Symmetry Breaking

Kaonic atoms measure the antikaon-nucleus interaction at almost zero relative energy, allowing one to determine basic low-energy quantum chromodynamics (QCD) quantities, namely, the antikaon-nucleon (K ¯ N) scattering lengths. The latter are important for extracting the sigma terms which are built on the symmetry breaking part of the Hamiltonian, thereby providing a measure of chiral and SU(3) symmetries breaking. After discussing the sigma terms and their relations to the kaonic atoms, we describe the most precise measurement in the literature of kaonic hydrogen, performed at LNF-INFN by the SIDDHARTA experiment. Kaonic deuterium is still to be measured, and two experiments are planned. The first, SIDDHARTA-2 at LNF-INFN was installed on DAΦNE in spring 2019 and will collect data in 2020. The second, E57 at J-PARC, will become operative in 2021