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The pixelation technique applied to FARCOS correlator in the CHIFAR experiment
Full text linkThe CHIFAR experiment, carried out at Laboratori Nazionali del Sud-INFN (INFN-LNS), was proposed to investigate the emission probability of Intermediate Mass Fragments (IMFs) in non-central Heavy Ion (HI) collisions. The aim was the study of the features of the Equation of State of the nuclear matter, focusing also on the role of the isospin degree of freedom of the colliding nuclei. The CHIMERA Collaboration has investigated at the incident beam energy of 20 AMeV some nuclear reactions including: 124Sn +64 Ni, 112Sn +58 Ni and 124Xe +64 Zn. The experimental setup was equipped with ten telescopes of the FARCOS (Femtoscope
ARray for COrrelation and Spectroscopy) correlator in its final configuration, coupled with the 4π CHIMERA multi-detector allowing the study of correlations among IMFs and light charged particles produced in a nuclear reaction. The results on the energy calibration, on the energy resolution and on the particle identification phase of the FARCOS correlator used in the CHIFAR experiment are reported. The socalled “pixelation technique” is the last step of the analysis explained here
Source function from two-particle correlations through deblurring: p-p and d-α pairs
Full text linkIn the study of heavy-ioncollisions, two-particle correlation functions (CF) give insights into the space-time characteristics of nuclear systems. Typically, those characteristics are quantified with the so-called source function (SF) related to CF through the Koonin-Pratt (KP) convolution formula. Deducing SF from CF is, at the formal level, an imaging problem. Here, we use the Richardson-Lucy (RL) optical deblurring algorithm, employed elsewhere in imaging problems, to extract the SF from two-particle correlation function measurements. We apply the algorithm to
the deuteron-alpha (d–α) and proton-proton (p-p) correlation data. In addition, we apply the Boltzmann-Uehling-Uhlenbeck (BUU) transport model to simulate the p-p source in heavy-ion collisions at low incident energies per nucleon (E/A). Comparing sources from BUU simulations with the RL algorithm results helps to understand the impact of fast and slow emissions on the sources. Consequently, we propose adding an analytically parametrized component to the BUU source to correct the missing secondary decay emissions in the model. In illustrating our approach, we rely on the p-p correlations measured in Ar + Sc reactions at E/A = 80 MeV
Constraints on the nuclear EOS from heavy-ion collision simulations
Full text linkWithin the transport model evaluation project (TMEP) of
simulations for heavy-ion collisions, we present a detailed study of the performance of different transport models for mean-field propagation in a box and in Sn+Sn collisions at 270 AMeV, with particular emphasis on the production of pions and Δ resonances, which are often employed as probes of the nuclear symmetry energy. Thus, we prescribe common and rather simple physics models, and follow in detail the results of several Boltzmann-Uehling-Uhlenbeck (BUU) models and quantum molecular dynamics (QMD) models. Concerning pion production, we find a convergence of the codes in the final charged pion yield ratio to a 1σ deviation of about 5%. However, the uncertainty is expected to be reduced to about 1.6% if improved Pauli blocking and calculation of the complex (non-linear) term in the mean-field potential are implemented in all codes
First characterization of innovative silicon carbide detectors for application in relative dosimetry with proton beams
Full text linkMonitoring the Percentage Depth-Dose distribution (PDD) is an essential phase of beam quality control protocols in proton therapy. The scientific community is exploring innovative techniques for more precise PDD assessment,
intending to apply them to high-intensity beam dosimetry. In this context, the progress made in the framework of the PRAGUE (Proton RAnGe measure Using silicon carbidE) project will be presented. The project’s purpose was the development of a real-time multilayer silicon carbide (SiC) detector, able to reconstruct the PDD of 30–150 MeV proton beams over a wide intensity range (106–1014 pps). This contribution describes the I-V (current vs. voltage) and C-V (capacitance vs. voltage) characterization of 80 SiC devices. The detectors’ stability and linearity are also introduced
Results and perspectives on multi-parton interactions with CMS
Full text linkThis contribution covers recent CMS experiment studies at the LHC, including the first direct observation of Double Parton Scattering (DPS) in same-sign WW boson production at √s = 13 TeV. Interest in DPS has shifted to flavour physics due to higher production cross-sections and better detector performance, enabling CMS to rival experiments like LHCb. Significant findings include the DPS signal in double Y analysis and double J/ψ production at √s =13TeV, which not only confirms the X(6900) resonance but highlights the DPS potential contribution. Additionally, the first observation of triple J/ψ production via Triple Parton Scattering (TPS)
Dark Sectors and Dark Photons search decaying into collimated leptons with the ATLAS experiment
Full text linkSeveral extensions of the Standard Model predict the existence of a Dark Sector weakly coupled to the Standard Model via the vector portal. The simplest extension of the Standard Model foresees the addition of a U(1) gauge group
and therefore of a new vector boson, the Dark Photon. At the Large Hadron Collider it is also possible to study Higgs portal models, which allows for the Higgs boson to decay into Dark Sector particles. These models results in Higgs decay processes that have two Dark Photons as their final state, which then decay into Standard Model particles, with highly collimated decay products. This work presents the ongoing search for the Dark Photon, with a mass between 17 MeV and 10 GeV, decaying promptly in the ATLAS detector into jets of collimated electrons and/or muons (Lepton-Jets). The analysis is performed by studying the entire Run-2 dataset at a center-of-mass energy of 13 TeV in proton-proton collisions
The CYGNO experiment
Full text linkThe existence of non-luminous matter in the Universe, known as Dark Matter, is a fundamental ingredient of modern cosmological theories. Its nature and characteristics are currently unknown. The CYGNO project, using a directional detector, aims to study events such as Dark Matter interactions in the low mass region O(GeV/c2). The proposed detector is a Time Projection Chamber (TPC), filled with a gas mixture of He:CF4 (60:40) at room temperature and at
mospheric pressure. The signal is produced by primary ionization from a few keV nuclear or electron recoil, which is amplified using a triple Gas Electron Multiplier (GEM) stack. During this process, light proportional to the primary electrons is generated. By combining the use of a sCMOS camera and photomultiplier, the signal is acquired allowing for the reconstruction of the energy and direction of the recoils. The R&D phase is concluding with the Long Imaging ModulE (LIME) prototype, a 50 liters TPC. It is currently taking data underground at the Laboratori Nazionali del Gran Sasso (LNGS) to study the performance of the prototype in a low background environment. The latest results on LIME operations in different configurations are shown
Euclid: The space mission and the spectroscopic sample
Full text linkEuclid is a European Space Agency (ESA) mission, designed to
investigate the nature of dark energy and dark matter. The satellite launch took place in July 2023, instrument commissioning and performance verification were completed successfully and data taking started in mid-February 2024. The survey will continue for the next six years covering one-third of the entire sky. It will map the matter distribution by measuring positions, shapes, and colors for billions of galaxies, and also redshift for a subset of tens of millions of those with unprecedented accuracy. This proceeding will present an overview of the mission, with particular attention to the spectroscopic analysis and its systematics
Quasi interactive high throughput analysis of high energy physics data
Full text linkIn this article a new quasi interactive platform for high throughput data analysis will be presented. The platform will leverage the cloud resources provided by ISCS (High-Performance Computing, Big Data e Quantum Computing Research Centre). An overview of the technologies used and preliminary results of some real use case will be shown
Time dependent CP violation measurements at Belle II
Full text linkTime dependent CP violation phenomena allow to precisely measure fundamental parameters of the Standard Model and search for New Physics. The Belle II experiment successfully completed the first phase of data tacking, collecting
a sample of e+e− annihilations corresponding to an integrated luminosity of 362 fb−1 at the Υ(4S) resonance. In this report we present the latest measurement of time dependent CP violation in the golden channel B0 → J/ψK0 S. This study uses for the first time a new flavour tagging algorithm, based on graph-neural-network, which increases the effective tagging efficiency by 18% (relative) compared to the previous algorithm. Finally, we present the first Belle II measurement in the channel B0 →ηK0 S, which is dominated by the loop amplitude