Archivio istituzionale della Ricerca - Scuola Normale Superiore
Not a member yet
27040 research outputs found
Sort by
Search for resonances decaying to an anomalous jet and a Higgs boson in proton–proton collisions at
No full text: This paper presents a search for new physics through the process where a massive particle, X, decays into a Higgs boson and a second particle, Y. The Higgs boson subsequently decays into a bottom quark-antiquark pair, which is reconstructed as a single large-radius jet. The decay products of Yare also assumed to produce a single large-radius jet. The identification of the Yparticle is enhanced by computing the anomaly score of its candidate jet using an autoencoder, which measures deviations from typical quark- or gluon-induced jets. This allows a simultaneous search for multiple Ydecay scenarios within a single analysis. In the main benchmark process, Yis a scalar particle that decays into a Wboson pair. Two other scalar Ydecay processes are also considered as benchmarks: decays to a light quark-antiquark pair, and decays to a top quark-antiquark pair. A fourth benchmark process considers Yas a hadronically decaying top quark, arising from the decay of a vector-like quark into a top quark and a Higgs boson. Data recorded by the CMS experiment at a center-of-mass energy of 13 TeV in 2016-2018, corresponding to an integrated luminosity of 138 fb-1 , are analyzed. The search covers Xmasses between 1.4 and 3.0 TeV and Ymasses between 90 and 400 GeV , with all simulated signals produced in the narrow-width approximation. No significant excess above the standard model background expectation is observed. The most stringent upper limits to date are placed on benchmark signal cross sections for various masses of X and Y particles
The Graph ∞-Laplacian Eigenvalue Problem
No full textWe analyze various formulations of the infinity-Laplacian eigenvalue problem on graphs, comparing their properties and highlighting their respective advantages and limitations. First, we investigate the graph infinity-eigenpairs arising as limits of p-Laplacian eigenpairs, extending key results from the continuous setting to the discrete domain. We prove that every limit of p-Laplacian eigenpair, for p going to infinity, satisfies a limit eigenvalue equation and establishes that the corresponding eigenvalue can be bounded from below by the packing radius of the graph, indexed by the number of nodal domains induced by the eigenfunction. Additionally, we show that the limits, for p going to infinity, of the variational p-Laplacian eigenvalues are bounded from both above and below by the packing radii, achieving equality for the smallest two variational eigenvalues and corresponding packing radii of the graph. In the second part of the paper, we introduce generalized infinity-Laplacian eigenpairs as generalized critical points and values of the infinity-Rayleigh quotient. We prove that the generalized variational infinity-eigenvalues equal the limit of the p-Laplacian variational eigenvalues and so satisfy the same upper bounds in terms of packing radii. Finally, we establish that any solution to the limit eigenvalue equation is also a generalized eigenpair, while any generalized eigenpair satisfies the limit eigenvalue equation on a suitable subgraph
Wikidata as a Knowledge Base for People of the Greco-Roman World
No full textWe explore the potential of Wikidata as a knowledge base (KB) for individuals associated with the Greco-Roman world, focusing on both the discoverability of relevant records and the current state of coverage. We develop a SPARQL query that combines multiple parameters to retrieve approximately 30,000 individuals and we propose several strategies to enhance the findability of the records. To assess coverage, we first compare the query results to a random sample of individuals described in the Realencyclopädie der classischen Altertumswissenschaft (Pauly–Wissowa), and then we evaluate how well Wikidata represents named individuals found in a corpus of ancient Greek and Latin texts
Documenting Italian Libraries on Wikidata: From Local Projects to a Multilayered National Knowledge Graph
No full textThe representation of Italian libraries in Wikidata has grown through two major data imports. In 2020, under commission from Tuscany region, the Sistema Cultura Toscana dataset was uploaded, raising the number of Italian libraries from fewer than 500 to 1,322 and documenting the methodology of this first large-scale project. A second step followed in 2022 with the addition of 11,239 entries from the ICCU Italian Libraries Database. This process involved merging CC0 datasets, entity alignment, and addressing gaps between the web versions of databases and their dumps. Together, these efforts illustrate both achievements and challenges in enriching Wikidata’s coverage of Italian libraries, specifically highlighting the role of iterative, human-curated workflows in large-scale data imports
Nonmonotonic and normative reasoning: a unified proof-theoretic framework
Full text linkRational agents are mostly located in dynamic environments, thereby handling incomplete information concerning the world and the rules that should govern their behavior. When elaborating such incomplete information, agents reach defeasible conclusions, that may be withdrawn when further information is available. Nonmonotonic logics are designed with the aim of modeling this mode of reasoning. This dissertation investigates different kinds of nonmonotonic logic through the lens of structural proof-theory.
Specifically, the thesis proposes a uniform proof-theoretic platform for monotonic and nonmonotonic extensions of classical propositional logic, based on combinations of sequents and antisequents (i.e., sequents for underivability) framed in suitable Gentzen-style calculi. The first case study is abductive reasoning, defined as the search for the missing premise in a deductively invalid argument. For any given abductive problem, we provide a syntactical procedure to generate an expected solution which does not coincide with the deductively minimal one, and which is a natural candidate for being the result of an inference to the best explanation. Next, we introduce the notion of hybrid hypersequent, where sequents and antisequents are composed in parallel to provide contrary updating on the derivation of the conclusion. We show that hybrid hypersequents are flexible enough to provide (weakly) analytic calculi for a number of logics for nonmonotonic and normative reasoning: default logics, a weak version of preferential logic R corresponding to base-generated belief revision, constrained I/O logics. Crucially, this proof-theoretic approach does not rely on ad hoc extensions of the underlying language to formalize extra-logical rules. Lastly, we present a modified notion of controlled sequent, where the turnstile is annotated with sets of formulas to prescribe what should or should not be entailed by the formulas in the antecedent. We introduce controlled sequent calculi for deontic reasoning grounded in default logic, showing that the introduction of suitable extra-logical rules permits to navigate paradoxical, dilemmatic or dynamic deontic scenarios in accordance with their intuitive assessment
‘That is the bet’ : theories of change in the strategies of the Italian climate movement
Full text linkResearch on differences within the climate movement has been focusing for a long time on the emergence of the ‘climate justice’ frame within this trajectory as a way out of a post-political understanding of climate action, as well as on tensions on the ‘radical’ vs. ‘reformist’ axis. Still, recent cases of climate action seem to call for a deeper analysis: while the climate justice framework is ubiquitous, internal differences within the movement are far from over. This article aims to address this issue, focusing on the strategic choices of movement actors. We aim to contribute to the literature on social movement strategies by pointing out the role of theories of change, i.e. the meta-strategic logics on how actors plan to achieve their goals and from which they derive their choice of targets, means, audience, and so on. Drawing on qualitative interivews to activists, our exploratory article proposes a framework to analyse theories of change and applies it to the three main actors of the Italian climate movement: Fridays For Future (FFF), Extinction Rebellion (XR) and Ultima Generazione (UG, part of the A22 network). Furthermore, the analysis points out how theories of change contribute to shaping how actors address strategic dilemmas
First Observation of CP Violation and Measurement of Polarization in B+ ->rho(770)0K*(892)+ Decays
No full textAn amplitude analysis of the B+->(pi+pi-)(KS0pi+) decay is performed in the mass regions 0.30<1.10 GeV/c2 and 0.75<1.20 GeV/c2, using pp collision data recorded with the LHCb detector corresponding to an integrated luminosity of 9 fb-1. [See attached file
Analytical Nuclear Gradients for the Multiconfigurational Self-Consistent Field Method Coupled with the Polarizable Fluctuating Charges Model
No full text: The multiscale model combining the multiconfigurational self-consistent field (MCSCF) method with the fully atomistic polarizable Fluctuating Charges (FQ) force field (Sepali, C.; et al. J. Chem. Theory Comput. 2024, 20, 9954-9967) is here extended to the calculation of analytical nuclear gradients. The gradients are derived from first-principles, implemented in the OpenMolcas package, and validated against numerical references. The resulting MCSCF/FQ nuclear gradients are employed to simulate vibronic absorption spectra of aromatic molecules in aqueous solution, namely benzene and phenol. By integrating this approach with molecular dynamics simulations, both solute conformational flexibility and the dynamical aspects of solvation are properly captured. The computed spectra reproduce experimental profiles and relative band intensities with remarkable accuracy, demonstrating the capability of the MCSCF/FQ model to simultaneously describe the multireference character of the solute and its interaction with the solvent environment
Interpretable Link Prediction via Neural-Symbolic Reasoning
No full textKnowledge Graph Embedding models have shown remarkable performances in different tasks like knowledge completion. However, they inherently lack interpretability, making it difficult to understand the reasoning behind their predictions. While different Neural-Symbolic (NeSy) models have been proposed to achieve interpretable reasoning through logic rules, existing evaluations primarily focus on accuracy, overlooking the critical assessment of explanation quality. This paper addresses this gap by introducing fully “interpretable-by-design” NeSy approaches for link prediction inspired by recently proposed models. Our framework employs reasoners that generate explicit logic proofs, utilizing either predefined or learned logic rules, ensuring transparent and explainable predictions. We go beyond traditional accuracy assessments, evaluating the quality of these explanations using established XAI metrics, including coherence. By quantitatively assessing the interpretability of our model, we aim to advance the development of trustworthy and understandable link prediction systems for Knowledge Graphs
Atomistic QM/Classical Modeling of Surface-Enhanced Infrared Absorption
Full text linkWe present a multiscale quantum mechanics/classical (QM/MM) approach for modeling surface-enhanced infrared absorption (SEIRA) spectra of molecules adsorbed on plasmonic nanostructures. The molecular subsystem is described at the density functional theory (DFT) level, while the plasmonic material is represented using fully atomistic, frequency-dependent Fluctuating Charges (omega FQ) and Fluctuating Charges and Dipoles (omega FQF mu) models. These schemes enable an accurate and computationally efficient description of the plasmonic response of both graphene-based materials and noble metal nanostructures, achieving accuracy comparable to that of ab initio methods. The proposed methodology is applied to the calculation of SEIRA spectra of adenine adsorbed on gold nanoparticles and graphene sheets. The quality and robustness of the approach are assessed through comparison with surface-enhanced Raman scattering (SERS) spectra and available experimental data. The results demonstrate that the proposed framework provides a reliable route to simulate vibrational responses of plasmon-molecule hybrid systems