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Toward a better characterization of the nuclear EOS using central collisions around Fermi energy
Get PDFThis study presents a novel approach to characterize the nu
clear equation of state (EOS) using central heavy-ion collisions in the Fermi energy domain. We analyze experimental data from Nickel-Nickel collisions at 52–90 MeV/nucleon, recorded with the INDRA 4π array at GANIL, employing Artificial Intelligence (AI) and Machine Learning (ML) techniques. Our methodology introduces a neural-network–based reconstruction of the impact parameter, trained on HIPSE and ELIE simulations, achieving sub-femtometer accuracy. This enables precise selection of central collision events for in-depth analysis. We then implement a Bayesian inference framework to estimate in-medium nucleon-nucleon crosssections, utilizing Kolmogorov-Smirnov probabilities calculated over an extensive set of global observables. Preliminary results demonstrate consistency with previous phenomenological studies, particularly for reactions below 100MeV/nucleon. The Bayesian approach provides both mean cross-section values and associated uncertainties, offering a more comprehensive characterization of nuclear medium effects. We discuss ongoing efforts to extend this methodology to estimate average and maximum densities reached in collisions, as well as plans to investigate the isospin dependence of the EOS using recent INDRA data. These advancements aim to provide improved constraints on the nuclear EOS across a range of densities and isospin asymmetries, contributing to our understanding of nuclear matter properties in both terrestrial experiments and astrophysical contexts
DualGain: A programmable multichannel amplifier system to increase dynamic range in nuclear physics digital ACQ architectures
Get PDFIn the framework of high granularity nuclear physics multidetectors, it is relevant to develop complex digital ACQ architectures. In this paper, we present a new high-frequency programmable multichannel amplifier system proposed for the CHIMERA and FARCOS detectors. The main system feature, other than very low signal degradation, modularity and remote programmability, is to improve the dynamic range of the ADC converters without the use of oversampling technique or the use of higher resolution ADC devices
Two-particle angular correlations of identified particles in pp and p--Pb collisions at LHC energies with ALICE
Get PDFThe two-particle angular correlations in the Δy,Δϕ space provide valuable insights into the properties of hadronization mechanisms and quark-gluon plasma properties. The correlation functions are influenced by several physical
sources, including mini-jet correlations, Bose-Einstein quantum statistics, resonance decays, conservation of energy and momentum, and other factors. Each correlation source has unique properties, and therefore each correlation function has a distinct form depending on transverse momentum and/or multiplicity. Previous results from angular correlation analysis of pp collisions at the LHC energies indicate an anti-correlation for pairs of baryons of the same sign in Δη,Δϕ space. This contradicts the predictions of Monte Carlo models, such as PYTHIA8 and EPOS. This study aims to investigate this behavior by exploring the correlation functions of different charge combinations of the detected particles (specifically, π±,K±, and p¯ p) and multiplicity classes in the Δy,Δϕ space for pp and p–Pb collisions at LHC energies. In addition, the study includes a comparison of the results obtained from both collision systems
Spheroidal expansion and freeze-out geometry of heavy-ion collisions in the few-GeV energy regime
Get PDFThe dissatisfactory results provided by various transport models to HADES Au+Au collisions have prompted a novel approach to the description of particle spectra. The use of statistical-hadronisation-based models is proposed. In
addition, a unique freeze-out hypersurface parametrisation is emplyed, which, with few kinematic parameters, is able to describe spectra of most abundant particles produced in the Au+Au √s NN =2.4 GeV most central collisions. A femtoscopic
correlation study of identical pions is showcased with moderate reproduction
Investigations of structure effects in heavy-ion fusion above the Coulomb barrier
Get PDFWe investigated the occurrence of nuclear structure effects in the fusion of heavy ions at above-barrier energies. To unveil the presence of such tiny effects, we developed a semi-classical model based on the modified Sum-of-Difference
method of nuclear reactions, able to reproduce the gross trend of the whole database available to date. The deviations between the model predictions and the data can
be linked, at low bombarding energies, to the occurrence of shell closures; at larger energies, such effects are washed out, while phenomena due to the cluster structure of projectile or target are observed
Orthogonal wave function dynamics in heavy-ion collisions
Get PDFA rich variety of phenomena characterises dissipative heavy-ion collisions, ranging from equilibration processes to the disintegration into fragments and nuclear clusters. The description of such a complex behaviour requires to track at the same time the evolution of the nuclear mean field and the effect of nucleonic degrees of freedom. We illustrate a solution to combine these two aspects within a unique
theoretical framework, starting from the time-dependent Hartree-Fock scheme and by introducing a dynamical basis of orthogonal fermionic wave functions
Description of many-body correlations and clustering phenomena within a unified theoretical scheme
Get PDFNuclear matter at subsaturation densities is expected to be inhomogeneous due to the emergence of many-body correlations, which are crucial for constructing a reliable equation of state. Specifically, large-scale correlations are responsible for fragmentation processes, experimentally observed in heavy-ion collisions at intermediate energies as the result of mechanical (spinodal) instabilities driven by the mean field, in connection to the occurrence of a liquid-gas phase transition. On the other hand, even at lower densities, owing to residual few-body correlations, light clusters like deuterons and strongly bound α particles also form but dissolve with increasing density due to the Pauli principle. Phenomenological models that make use of energy density functionals offer a way to include these clusters as additional degrees of freedom, yet a consistent description of both light clusters and heavy fragment formation through spinodal instabilities is still lacking. In this work, we propose a novel approach to incorporate in-medium modified clusters within a non-relativistic kinetic framework, unifying the description of clustering phenomena and heavy fragment formation at low densities
NARCOS: A new correlator for neutrons and charged particles
Get PDFThe simultaneous neutron and charged particles detection in heavy ion collisions is mandatory in the investigation of reaction mechanisms and in the study of the spectroscopy of nuclear states, characterized by neutron emission. The
NarCoS (Neutron Array for Correlation Studies) array is a compact, modular, segmented transportable apparatus, consisting of EJ276G plastic scintillators, with excellent neutron detection capabilities and that combine the relevant neutron detection efficiency to high angular and energy resolution. It consists of an array of elementary detection cells of scintillators, optically coupled with a SiPM (Silicon PhotoMultiplier), to be arranged in various geometries, according to the case. The scintillating elementary cell has a dimension of 3cm×3cm×3cm. The construction and the development of such apparatus are realized in the framework of the Italian PRIN2020 ANCHISE project (Array for Neutron and Charged particles with HIgh
linear momentum SElection). This contribution presents test results conducted with various types of sources and those relative to the preliminary analysis of the data obtained from the CROSSTEST experiment performed at the Laboratori Nazionali di Legnaro, to investigate the discrimination capabilities of the array
Detecting scintillation light of NaI crystals with SiPMs at cryogenic temperature
Get PDFThe direct search for dark matter interaction is a main open issue in astroparticle physics, and a promising technique is based on scintillation light detection with NaI(Tl) crystals to validate of refute the DAMA/LIBRA claim. The signal is observed in the (1 to 6) keV energy interval, where the main source of background is due to noise from the Photomultiplier Tubes used by all current generation experiments. This paper presents the ASTAROTH Project, whose goal is to achieve a significantly higher signal-to-noise ratio at the energies of interest and a lower threshold, by reading out the light from of NaI(Tl) crystals using arrays
of cryogenic SiPMs. We present the characterisation of a first SiPM array with laser light in liquid nitrogen and the results of a cool-down of ASTAROTH’s custom cryostat where a NaI(Tl) crystal is coupled to the array
The Value of Science and Technology in Addressing the Great Challenges of Our Time
Get PDFIl volume raccoglie gli Atti della XIII edizione della “Italy-China Science, Technology and Innovation Week”, tenutasi a Napoli e a Venezia dal 26 al 28 novembre 2024.
I contributi, volti a sottolineare il valore della scienza e delle nuove tecnologie nell’affrontare le grandi sfide del nostro tempo spaziano dall’agroalimentare al cambiamento climatico e biodiversità, dalle scienze polari agli ambienti marino e costieri, dalle tecnologie della produzione a quelle per la riduzione del rischio e dei disastri.
The volume collects the proceedings of the 13th edition of the “Italy-China Science, Technology and Innovation Week,” held in Naples and Venice from November 26 to 28, 2024.
The contributions, aimed at highlighting the value of science and new technologies in addressing the great challenges of our time, range from agri-food to climate change and biodiversity, from polar sciences to marine and coastal environments, and from production technologies to those for risk and disaster reduction