Modern sedimentary facies in a progradational barrier-spit system, Goro lagoon, Po delta, Italy

Barriers and spits connected to fluvial sedimentary sources represent environments which tend to evolve rapidly and experience sudden transformations, mainly driven by changes in sediment supply and path. As a consequence, the variability of facies is significant even within small sedimentary records. The 7 km long barrier-spit system facing the Goro Lagoon, and fed by the mouth of the Po di Goro, is a typical example of an accretionary coastal morphotype, suitable to describe adjacent nearshore depositional environments and their stratigraphic signatures, variability, and relationships. Thirteen short cores of sediment were sampled in order to represent the variable depositional subenvironments from the shoreface (prodelta-delta front) to the back barrier, crossing the active barrier-spit and the ancient spit arms and relative swales. The description of the modern sedimentary records, improved upon using core X-rays, has been coupled with information on the morphological changes which occurred during the period of maximum spit development (1955\u20132000), based on available aerial photos and a cartographic/topographic dataset. The results obtained allow for the description and interpretation of the depositional environments changing at the human-scale. Sediments of the upper shoreface are quite uniform, composed by evenly laminated sands; the transition between delta front and prodelta at a depth of 6m is marked by the alternation of sand and mud beds. These reflect the periodic changes in sediment supply by the river, as well as storm events. The most recent spit branch and the relative back barrier-swale environment are the results of the rapid progradation of the spit system, which implies phases of rapid longshore growth, hooked spit development, cannibalization, overwash, and breaching. Morphodynamic changes have resulted in an overlap of short sedimentary records where stratigraphic signatures are linked either to phases of sediment transport and selection by waves and tidal currents (cross-bedding, foreset, and planar laminated sands, shell imbrication, massive beds) or to phases of sedimentary stasis when biological activity is predominant (algal mat and bioturbation). Human signature is also well marked inside the stratigraphic record. Clam harvesting is carried out within the lagoon, causing the physical disturbance and winnowing of the superficial sediment, thus inducing the local formation of graded beds and shell rehash

VIP-2 —High-Sensitivity Tests on the Pauli Exclusion Principle for Electrons

The VIP collaboration is performing high sensitivity tests of the Pauli Exclusion Principle for electrons in the extremely low cosmic background environment of the underground Gran Sasso National Laboratory INFN (Italy). In particular, the VIP-2 Open Systems experiment was conceived to put strong constraints on those Pauli Exclusion Principle violation models which respect the so-called Messiah–Greenberg superselection rule. The experimental technique consists of introducing a direct current in a copper conductor, and searching for the X-rays emission coming from a forbidden atomic transition from the L shell to the K shell of copper when the K shell is already occupied by two electrons. The analysis of the first three months of collected data (in 2018) is presented. The obtained result represents the best bound on the Pauli Exclusion Principle violation probability which fulfills the Messiah–Greenberg rule

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

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

Experimental test of Non-Commutative Quantum Gravity by VIP-2 Lead

Pauli Exclusion Principle (PEP) violations induced by space-time non-commutativity, a class of universality for several models of Quantum Gravity, are investigated by the VIP-2 Lead experiment at the Gran Sasso underground National Laboratory of INFN. The VIP-2 Lead experimental bound on the non-commutative space-time scale $\Lambda$ excludes $\theta$-Poincar\'e far above the Planck scale for non vanishing ``electric-like" components of $\theta_{\mu \nu}$, and up to $6.9 \cdot 10^{-2}$ Planck scales if they are null. Therefore, this new bound represents the tightest one so far provided by atomic transitions tests. This result strongly motivates high sensitivity underground X-ray measurements as critical tests of Quantum Gravity and of the very microscopic space-time structure.Comment: 13 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:2209.0007

Strongest atomic physics bounds on Non-Commutative Quantum Gravity Models

Investigations of possible violations of the Pauli Exclusion Principle represent critical tests of the microscopic space-time structure and properties. Space-time non-commutativity provides a class of universality for several Quantum Gravity models. In this context the VIP-2 Lead experiment sets the strongest bounds, searching for Pauli Exclusion Principle violating atomic-transitions in lead, excluding the $\theta$-Poincar\'e Non Commutative Quantum Gravity models far above the Planck scale for non-vanishing $\theta_{\mu \nu}$ ``electric-like'' components, and up to $6.9 \cdot 10^{-2}$ Planck scales if $\theta_{0i} = 0$.Comment: 7 pages, 2 figure

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

High precision kaonic deuterium measurement at the DAΦNE collider : the SIDDHARTA-2 experiment and the SIDDHARTINO run

The kaonic deuterium 2p → 1s transition X-ray measurement, a fundamental information needed for a deeper understanding of the Quantum ChromoDynamics (QCD) in the strangeness sector, is still missing. The SIDDHARTA-2 collaboration is now ready to achieve this unprecedented result thanks to the dedicated experimental apparatus that will allow to obtain the values of the kaonic deuterium K-transitions with a precision comparable to the most precise kaonic hydrogen measurement to-date performed by SIDDHARTA in 2009. Both the kaonic hydrogen and kaonic deuterium X-ray spectroscopy measurements of the de-excitation towards the fundamental level are a direct probe on KN interaction at threshold, as opposed to the scattering experiments which need an extrapolation to zero energy. Combining these results through the Deser-Truemann like formula, the isospin-dependent kaon-nucleon scattering lengths can be obtained in a model-independent way. The SIDDHARTA-2 setup is presently installed at the DAΦNE (Double Annular Φ Factory for Nice Experiments) collider of Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali di Frascati and it is ready to perform the challening kaonic deuterium measurement. This paper provides an overview on the SIDDHARTA-2 experimental apparatus and a preliminary result of the kaonic helium run, preparatory for the SIDDHARTA-2 data taking campaign, is also presented