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Prospects for combined analyses of hadronic emission from -ray sources in the Milky Way with CTA and KM3NeT
No full textThe Cherenkov Telescope Array and the KM3NeT neutrino telescopes are major upcoming facilities in the fields of -ray and neutrino astronomy, respectively. Possible simultaneous production of rays and neutrinos in astrophysical accelerators of cosmic-ray nuclei motivates a combination of their data. We assess the potential of a combined analysis of CTA and KM3NeT data to determine the contribution of hadronic emission processes in known Galactic -ray emitters, comparing this result to the cases of two separate analyses. In doing so, we demonstrate the capability of Gammapy, an open-source software package for the analysis of -ray data, to also process data from neutrino telescopes. For a selection of prototypical -ray sources within our Galaxy, we obtain models for primary proton and electron spectra in the hadronic and leptonic emission scenario, respectively, by fitting published -ray spectra. Using these models and instrument response functions for both detectors, we employ the Gammapy package to generate pseudo data sets, where we assume 200 h of CTA observations and 10 years of KM3NeT detector operation. We then apply a three-dimensional binned likelihood analysis to these data sets, separately for each instrument and jointly for both. We find that the largest benefit of the combined analysis lies in the possibility of a consistent modelling of the -ray and neutrino emission. Assuming a purely leptonic scenario as input, we obtain, for the most favourable source, an average expected 68% credible interval that constrains the contribution of hadronic processes to the observed -ray emission to below 15%
Development towards high-resolution kHz-speed rotation-free volumetric imaging
No full textX-ray multi-projection imaging (XMPI) has the potential to provide rotation-free 3D movies of optically opaque samples. The absence of rotation enables superior imaging speed and preserves fragile sample dynamics by avoiding the centrifugal forces introduced by conventional rotary tomography. Here, we present our XMPI observations at the ID19 beamline (ESRF, France) of 3D dynamics in melted aluminum with 1000 frames per second and 8 µm resolution per projection using the full dynamical range of our detectors. Since XMPI is a method under development, we also provide different tests for the instrumentation of up to 3000 frames per second. As the high-brilliance of 4th generation light-sources becomes more available, XMPI is a promising technique for current and future X-ray imaging instruments
Multiplicity dependence of σ/σ in pp collisions at = 13 TeV
No full textThe ratio of production cross-sections of ψ(2S) over J/ψ mesons as a function of charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy = 13 TeV is measured with a data sample collected by the LHCb detector, corresponding to an integrated luminosity of 658 pb. The ratio is measured for both prompt and non-prompt ψ(2S) and J/ψ mesons. When there is an overlap between the rapidity ranges over which multiplicity and charmonia production are measured, a multiplicity-dependent modification of the ratio is observed for prompt mesons. No significant multiplicity dependence is found when the ranges do not overlap. For non-prompt production, the ψ(2S)-to-J/ψ production ratio is roughly independent of multiplicity, irrespective of the rapidity range over which the multiplicity is measured. The results are compared to predictions of the co-mover model and agree well except in the low multiplicity region. The ratio of production cross-sections of ψ(2S) over J/ψ mesons are cross-checked with other measurements in di-lepton channels and found to be compatible.[graphic not available: see fulltext
Measurement of the <math display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>-</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>-</mo></msup></math> cross section from threshold to 1.2 GeV with the CMD-3 detector
No full textThe cross section of the process e+e-→π+π- has been measured in the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on a full dataset collected below 1 GeV during three data taking seasons, corresponding to an integrated luminosity of about 62 pb-1. In the dominant ρ-resonance region, a systematic uncertainty of 0.7% has been reached. At energies around ϕ-resonance the π+π- production cross section was measured for the first time with high beam energy resolution. The forward-backward charge asymmetry in the π+π- production has also been measured. It shows a strong deviation from the theoretical prediction based on the conventional scalar quantum electrodynamics framework, and it is in good agreement with the generalized vector-meson-dominance and dispersive-based predictions. The impact of the presented results on the evaluation of the hadronic contribution to the anomalous magnetic moment of muon is discussed
AI Playground for INFN Scientific Use Cases
Get PDF<p>Talk given at "Workshop sul Calcolo nell'INFN", Palau (Sassari), 20-24/05/2024</p>\n\n<p>Title: </p>\n\n<p><strong>AI Playground:</strong> a curated collection of technologies offered “as a Service” on top of INFN Cloud for fast prototyping Machine Learning solutions across INFN research areas. </p>\n\n<p>Abstract: </p>\n\n<p>The introduction of <strong>ChatGPT</strong> in November 2022 has gained widespread attention and significantly boosted <strong>Generative AI </strong>adoption in technological solutions, highlighting the <strong>potential of AI</strong> to automate tasks, analyze large datasets, and make predictions with high accuracy. </p>\n\n<p>The fast-paced adoption of AI techniques has also been possible by the development and general availability of <strong>AI frameworks, libraries and platforms</strong> that provide structured approaches that make it easier to implement AI solutions. </p>\n\n<p>The integration of AI and Machine Learning (ML) in the <strong>Physics </strong>domain is also becoming increasingly pervasive, transforming the way scientists approach and solve complex problems. For instance, ML techniques in the High Energy Physics (HEP) domain are ubiquitous, successfully used in many areas and are playing a significant role in LHC Run 3 and in the future High-Luminosity LHC upgrade. </p>\n\n<p><strong>INFN</strong> always stands at the frontier’s edge of the most innovative technological advancements, hence supporting AI as a promising approach across the diverse research areas. </p>\n\n<p>However, AI adoption requires researchers at INFN to solve not only problems related to the specificity of the application/experiment (e.g., tailored models and specialized domain knowledge), but also requires solving general infrastructure-level and ML-workflow related problems. </p>\n\n<p>In this regard, we introduce <strong>AI Playground</strong>, a curated collection of technologies offered “<strong>as a Service</strong>” on top of INFN Cloud, for fast prototyping Machine Learning solutions across INFN research areas. </p>\n\n<p>AI Playground leverages <strong>INFN Cloud</strong> resources and principles by providing an open-source solution to INFN users that can be deployed through the INFN Cloud Dashboard. </p>\n\n<p>The general idea behind the design of AI Playground is to address common use cases within the institute, collect reliable and consolidated technologies to solve these problems, then offer these technologies within the playground so that scientists can easily <strong>prototype</strong> their AI solutions for use cases that benefit of the same technologies. </p>\n\n<p>In this contribution we introduce the principles and high-level architecture of AI Playground and address two use cases in different domains that have been prototyped within the playground. </p>\n\n<p>The first use case is in the <strong>NLP</strong> domain: we expose through an INFN Cloud HTTP endpoint a RAG (Retrieval Augmented Generation) pipeline: RAG is a popular technique for injecting knowledge into a Large Language Model (LLM). We describe the RAG pipeline implemented through on-premises model serving of open source LLMs. </p>\n\n<p>The second use case is in the <strong>HEP </strong>domain: we expose through an INFN Cloud HTTP endpoint a model for inference related to a signal-vs-noise discrimination problem about data generated by particle collisions. </p>\n\n<p>The two use cases belong to different research areas but leverage the same AI Playground technologies. </p>\n\n<p>AI Playground is currently a work in progress, the aim is that its <strong>application-agnostic</strong> nature will serve as a unified ecosystem where developers, data scientists, and domain experts can leverage a standardized framework for ML model development and deployment. Hopefully, the playground will eliminate the need for extensive domain expertise in every application area, empowering a broader audience to leverage the benefits of machine learning, breaking down barriers and fostering innovation across diverse research domains.</p>
Neutrino Chess
Get PDF<p>Neutrino Chess è un gioco da tavolo di strategia astratta (simile agli scacchi/dama) dove le mosse delle pedine sono ispirate al fenomeno di oscillazione del sapore dei neutrini. Questo semplice gioco può essere utilizzato per spiegare l'esistenza e il comportamento di queste particelle e l'importanza della misura delle loro masse, insieme al concetto di osservabili quantistiche in basi diverse.</p>
Development of the CMS detector for the CERN LHC Run 3
No full textSince the initial data taking of the CERN LHC, the CMSexperiment has undergone substantial upgrades and improvements. Thispaper discusses the CMS detector as it is configured for the thirddata-taking period of the CERN LHC, Run 3, which started in2022. The entire silicon pixel tracking detector was replaced. A newpowering system for the superconducting solenoid was installed. Theelectronics of the hadron calorimeter was upgraded. All the muonelectronic systems were upgraded, and new muon detector stationswere added, including a gas electron multiplier detector. Theprecision proton spectrometer was upgraded. The dedicated luminositydetectors and the beam loss monitor were refurbished. Substantialimprovements to the trigger, data acquisition, software, andcomputing systems were also implemented, including a new hybridCPU/GPU farm for the high-level trigger
Curvature-bias corrections using a pseudomass method
No full textMomentum measurements for very high momentum chargedparticles, such as muons from electroweak vector boson decays, areparticularly susceptible to charge-dependent curvature biases thatarise from misalignments of tracking detectors. Low momentum chargedparticles used in alignment procedures have limited sensitivity tocoherent displacements of such detectors, and therefore are unableto fully constrain these misalignments to the precision necessaryfor studies of electroweak physics. Additional approaches aretherefore required to understand and correct for these effects. Inthis paper the curvature biases present at the LHCb detector arestudied using the pseudomass method in proton-proton collision datarecorded at centre of mass energy √(s)=13 TeV during 2016,2017 and 2018. The biases are determined using Z→μμdecays in intervals defined by the data-taking period, magnetpolarity and muon direction. Correcting for these biases, which aretypically at the 10 GeV level, improves the Z→μμ mass resolution by roughly 18% and eliminatesseveral pathological trends in the kinematic-dependence of the meandimuon invariant mass
Improved Measurement of <math display="inline"><mi>C</mi><mi>P</mi></math> Violation Parameters in <math display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>-</mo></msup></math> Decays in the Vicinity of the <math display="inline"><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> Resonance
No full textThe decay-time-dependent CP asymmetry in Bs0→J/ψ(→μ+μ-)K+K- decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 6 fb-1, collected with the LHCb detector at a center-of-mass energy of 13 TeV. Using a sample of approximately 349 000 Bs0 signal decays with an invariant K+K- mass in the vicinity of the ϕ(1020) resonance, the CP-violating phase ϕs is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the Bs0-B¯s0 system, ΔΓs, and the difference of the average Bs0 and B0 meson decay widths, Γs-Γd. The values obtained are ϕs=-0.039±0.022±0.006 rad, ΔΓs=0.0845±0.0044±0.0024 ps-1, and Γs-Γd=-0.056-0.0015+0.0013±0.0014 ps-1, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements to date and are consistent with expectations based on the Standard Model and with the previous LHCb analyses of this decay. These results are combined with previous independent LHCb measurements. The phase ϕs is also measured independently for each polarization state of the K+K- system and shows no evidence for polarization dependence
Optimal encoding of two dissipative interacting qubits
No full textWe investigate a system of two coupled qubits interacting with an Ohmic bath as a physical model for the implementation of one logical qubit. In this model, the interaction with the other qubit represents unitary noise, while the Ohmic bath is responsible for finite temperature. In the presence of a one-dimensional decoherence-free subspace (DFS), we show that, while this is not sufficient to protect a qubit from decoherence, it can be exploited to encode one logical qubit with greater performance than the physical one. We show different possible strategies for the optimal encoding of a logical qubit through a numerical analysis based on matrix product states. This method reproduces faithfully the results of perturbative calculations, but it can be extended to cases of crucial interest for physical implementations, e.g., in the case of strong coupling with the bath. As a result, a logical qubit encoded in the subspace which is the direct sum of the antiferromagnetic states in the Bell basis, namely the DFS and the antiferromagnetic state in the triplet, is the optimally robust one, as it takes advantage of both the anchoring to the DFS and the protection from the antiferromagnetic interaction