Today, Monday 8 June, the painting Ecce Homo by Antonello da Messina, a Renaissance masterpiece of the 15 century, arrives at the National Museum of Abruzzo (MuNDA) in L’Aquila, where it will become part of the museum’s permanent collection.
The work, recently acquired by the Italian State, has been the subject of a study and restoration campaign at the Central Institute for Restoration (ICR), with an integrated programme of investigative analyses, conservation assessments and preliminary interventions aimed at ensuring its stability, legibility and proper display, in which INFN took part.
The work carried out at the ICR involved conservators, art historians and diagnostic specialists, including a team of physicists, with the aim of thoroughly reconstructing the constituent materials, execution techniques, any overpainting and previous interventions.
Specifically, the National Institute for Nuclear Physics (INFN) participated in the investigations with a portable multi-analytical scanner developed within the Artemisia project, funded by the Lazio Region as part of the DTC Centre of Excellence. The system, unique of its kind, integrates several non-invasive diagnostic techniques – Fourier Transform Infrared Spectroscopy (FTIR), X-ray Fluorescence (XRF), UV Fluorescence and Fibre Optic Reflectance Spectroscopy (FORS) – into a single platform designed to operate directly on the artwork. The integration of these techniques is a distinctive feature of this instrument and makes it possible to obtain, on the same analysed point, both elemental information (through XRF) and molecular information (through FTIR).
The campaign focused on the acquisition of infrared maps with spatial resolution on the order of a millimetre, making it possible to obtain a detailed chemical representation of the painted surface. Infrared analysis enabled the identification of organic binders, varnishes, restoration materials and degradation products, contributing to the construction of a comprehensive body of knowledge, indispensable for guiding conservation interventions.
The investigations conducted by INFN formed part of a broader diagnostic campaign coordinated by the ICR, involving a wide range of expertise and infrastructures. Alongside FTIR and XRF spectroscopic analyses, the campaign included hyperspectral investigations carried out by CNR-ISPC of Florence and Lecce, high-resolution photographic documentation using a stereomicroscope and a Hirox digital microscope, and analyses of micro-samples using SEM-EDS, Micro-Raman and GC-MS performed by the ICR scientific laboratories.
“The integration of different techniques makes it possible to correlate chemical, material and conservation information in a coherent manner, while maintaining a completely non-invasive approach,” underlines Mariangela Cestelli Guidi, Head of the DAFNE-Luce Laboratory at the INFN National Laboratories of Frascati and member of CHNet, the cultural heritage network of the National Institute for Nuclear Physics.
The DAFNE-Luce Laboratory is the synchrotron light laboratory of the INFN National Laboratories of Frascati. Synchrotron light is a fundamental tool for carrying out advanced research in fields such as materials science, chemistry, biology, medicine, environmental sciences and cultural heritage. The laboratory is a reference centre for the analysis of paintings, thanks to the integration of complementary techniques, both laboratory-based and portable, which make it possible to connect in situ investigations and detailed analyses.
In particular, the synchrotron light laboratory makes it possible to illuminate sections of artworks with highly collimated and brilliant beams, characterised by high intensity and low divergence. This allows the acquisition of high-contrast images and significantly improves sensitivity in detecting minor components and distinguishing thin layers, providing a more precise interpretation of the pictorial microstratigraphy.
The Ecce Homo campaign therefore represents an emblematic example of integration between scientific research, advanced diagnostics and conservation. In this process, knowledge becomes the fundamental prerequisite for the protection and enhancement of the artwork, in line with a vision that brings together multidisciplinary expertise and innovative technologies in order to return to the public a heritage that is fully understood and accessible.
ARTEMISIA project information: https://dtclazio.it/artemisia-infn
DAFNE-Luce Laboratory: https://w3.lnf.infn.it/acceleratori/dafne-luce
Mappatura a infrarossi della distribuzione degli ossolati di calcio sul dipinto Ecce Homo realizzata da INFN nell'ambito del progetto Artemisia. Crediti INFN
L’analisi si basa sulla selezione di eventi caratterizzati dalla presenza di un muone, almeno un protone e nessun pione, effettuata mediante due approcci, automatici e indipendenti, di ricostruzione degli eventi: Pandora e SPINE, quest’ultimo interamente basato su tecniche di intelligenza artificiale. I due approcci hanno raggiunto efficienze di identificazione del possibile segnale rispettivamente del 48% e del 78%, e purezze dell’82% e del 91%. Un trattamento approfondito delle incertezze sistematiche ha consentito di valutare in modo accurato il flusso di neutrini del Booster Neutrino Beam, le interazioni dei neutrini in argon liquido e le prestazioni del rivelatore.
La collaborazione ICARUS non ha osservato alcuna evidenza statisticamente significativa di scomparsa di neutrini muonici nello spettro energetico delle interazioni di corrente carica. Sono state quindi tracciate delle curve di esclusione con un livello di confidenza del 90%. In pratica, queste curve indicano quali valori di alcuni parametri fisici caratteristici – la differenza tra i quadrati delle masse dei neutrini coinvolti e l’ampiezza della probabilità di oscillazione dei neutrini muonici – non sono compatibili con i dati osservati. Il contorno dei risultati sperimentali ottenuti dall’esperimento si trova quasi completamente all’interno della regione di sensibilità prevista, entro circa una deviazione e mezza standard, quindi in buon accordo con le aspettative.
Pur con le limitazioni intrinseche a un’analisi di scomparsa di neutrini muonici condotta con un singolo rivelatore, questi primi risultati rappresentano una tappa fondamentale per il programma Short-Baseline Neutrino. Essi dimostrano l’elevata qualità dei dati raccolti con ICARUS e la piena idoneità del rivelatore per analisi di fisica di precisione, nonché la maturità degli strumenti software per la selezione degli eventi, l’analisi statistica e la simulazione del rivelatore.
I risultati ottenuti, uniti all’operatività congiunta con il rivelatore vicino SBND – esposto allo stesso fascio di neutrini ma a distanza inferiore dalla sorgente – aprono la strada a un’analisi combinata a due rivelatori solida e competitiva a livello internazionale. Il successo di questa misura dimostra la validità e l’efficacia sperimentale della tecnica ad argon liquido che sta alla base del futuro esperimento DUNE.
