Observations of the singly Cabibbo-suppressed decays Ξc+→pKS0 {\Xi}_c^{+}\to p{K}_S^0 , Ξc+→Λπ+ {\Xi}_c^{+}\to \Lambda {\pi}^{+} , and Ξc+→Σ0π+ {\Xi}_c^{+}\to {\Sigma}^0{\pi}^{+} at Belle and Belle II

Using data samples of 983.0 fb(-1) and 427.9 fb(-1) accumulated with the Belle and Belle II detectors operating at the KEKB and SuperKEKB asymmetric-energy e(+)e(-) colliders, singly Cabibbo-suppressed decays Xi(+)(c) -> pK(S)(0), Xi(+)(c) -> Lambda pi(+), and Xi(+)(c) -> Sigma(0)pi(+) are observed for the first time. The ratios of branching fractions of Xi(+)(c) -> pK(S)(0), Xi(+)(c) -> Lambda pi(+), and Xi(+)(c) -> Sigma(0)pi(+) relative to that of Xi(+)(c) -> Xi(-)pi(+)pi(+) are measured to beB(Xi(+)(c) -> pK(S)(0))/B(Xi(+)(c) -> Xi(-)pi(+)pi(+)) = (2.47 +/- 0.16 +/- 0.07%),B(Xi(+)(c) -> Lambda pi(+))/B(Xi(+)(c) -> Xi(-)pi(+)pi(+)) = (1.56 +/- 0.14 +/- 0.09%),B(Xi(+)(c) -> Sigma(0)pi(+))/B(Xi(+)(c) -> Xi(-)pi(+)pi(+)) = (4.13 +/- 0.26 +/- 0.22)%.Multiplying these values by the branching fraction of the normalization channel, B(Xi(+)(c) -> Xi(-)pi(+)pi(+)) = (2.9 +/- 1.3%, the absolute branching fractions are determined to beB(Xi(+)(c) -> pK(S)(0)) = (7.16 +/- 0.46 +/- 0.20 +/- 3.21) x 10(-4),B(Xi(+)(c) -> Lambda pi(+)) = (4.52 +/- 0.41 +/- 0.26 +/- 2.03) x 10(-4),B(Xi(+)(c) -> Sigma(0)pi(+)) = (1.20 +/- 0.08 +/- 0.07 +/- 0.54) x 10(-3).The first and second uncertainties above are statistical and systematic, respectively, while the third ones arise from the uncertainty in B(Xi(+)(c) -> Xi(-)pi(+)pi(+))

Gossip-Based Estimation of Centroid and Common Reference Frame in Open Multi-Agent Systems

Decentralized estimation of centroid and common reference frame in multi-agent systems is a challenging problem, particularly when agents do not have access to global positioning data. This challenge intensifies in Open Multi-Agent Systems (OMAS), where the network composition dynamically changes due to agents joining or leaving, causing fluctuations in the number of participants. This paper presents a novel, decentralized gossip-based algorithm that enables agents in OMAS to collaboratively estimate both the centroid and a common reference frame in a 2-D environment where the number of agents may fluctuate over time. Notably, our approach remains robust despite noisy distance measurements and intermittent participation, as it relies on asynchronous, local pairwise interactions. Designed to accommodate the dynamic nature of network topologies, our algorithm can be employed for real-world applications where agents can join or leave the system due to failures, resource limitations or external environmental factors

La neutralità tecnologica: un nuovo principio del diritto dell'ambiente?

Il diritto positivo è sempre più pervaso dal concetto di neutralità tecnologica, anche con riferimento alla normativa in materia di transizione ecologica e tutela dell’ambiente. Si tratta di un principio giuridico? Afferisce al diritto dell’ambiente? Il legislatore e le amministrazioni sono tenuti al suo rispetto nella produzione e attuazione di regole giuridiche? Sebbene l’esame della normativa vigente sembri prospettarne la qualificazione come principio giuridico espresso settoriale, ma difficilmente applicabile nell’attuazione delle politiche ambientali, nel contributo saranno esposti taluni elementi che renderebbero adattabile lo stesso anche nella materia ambientale.Positive law is increasingly influenced by the concept of technological neutrality, including in relation to regulations on ecological transition and environmental protection. Is this a principle of law? Does it pertain to environmental law? Are legislators and administrations required to comply with it in the creation and implementation of legal rules? While an analysis of the current legislation suggests its classification as an expressed sectoral legal principle, albeit one that is difficult to apply in the implementation of environmental policies, this contribution will present certain elements that could make it adaptable to the environmental field as well

Tra virtù teologale e principio speranza. Rinvii e intersezioni: Charles Peguy, Ernst Bloch, Paul Ricoeur, Ernesto Balducci.

Prendendo spunto da una poesia di Charles Peguy sulla virtù teologale della speranza, si prende in esame la sua intrecciata valenza inframondana-secolare e trascendentale-escatologica. E', poi, ricostruito, nel contesto delle grandi trasformazioni economiche, sociali e culturali tra Ottocento e Novecento, il dibattito teologicvo-pastoraledalla Rerum Novarum alla Gaudium et Spes, con i contributi di riflessione foilosofica di Chjarles Peguy, Jurghen Moltmann, Erst Bloch, Paul Ricoeur e Ernesto Balducci

X-Ray Polarization of the High-synchrotron-peak BL Lacertae Object 1ES 1959+650 during Intermediate and High X-Ray Flux States

We report the Imaging X-ray Polarimetry Explorer (IXPE) polarimetric and simultaneous multiwavelength observations of the high-energy-peaked BL Lacertae object (HBL) 1ES 1959+650, performed in 2022 October and 2023 August. In 2022 October, IXPE measured an average polarization degree ΠX = 9.4% ± 1.6% and an electric-vector position angle ψX = 53° ± 5°. The polarized X-ray emission can be decomposed into a constant component, plus a rotating component, with the rotation velocity ωEVPA = (−117 ± 12) deg day−1. In 2023 August, during a period of pronounced activity of the source, IXPE measured an average ΠX = 12.4% ± 0.7% and ψX = 20° ± 2°, with evidence (∼0.4% chance probability) for a rapidly rotating component with ωEVPA = 1864 ± 34 deg day−1. These findings suggest the presence of a helical magnetic field in the jet of 1ES 1959+650 or stochastic processes governing the field in turbulent plasma. Our multiwavelength campaigns from radio to X-ray reveal variability in both polarization and flux from optical to X-rays. We interpret the results in terms of a relatively slowly varying component dominating the radio and optical emission, while rapidly variable polarized components dominate the X-ray and provide minor contribution at optical wavelengths. The radio and optical data indicate that on parsec scales the magnetic field is primarily orthogonal to the jet direction. On the contrary, X-ray measurements show a magnetic field almost aligned with the parsec jet direction. Confronting with other IXPE observations, we guess that the magnetic field of HBLs on subparsec scale should be rather unstable, often changing its direction with respect to the Very Long Baseline Array jet

Search for same-charge top-quark pair production in pp collisions at sqrt(s) = 13 TeV with the ATLAS detector

A search for the production of top-quark pairs with the same electric charge (tt or (tt) over bar) is presented. The analysis uses proton-proton collision data at root s = 13 TeV, recorded by the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb(-1). Events with two same-charge leptons and at least two b-tagged jets are selected. Neural networks are employed to define two selections sensitive to additional couplings beyond the Standard Model that would enhance the production rate of same-sign top-quark pairs. No significant signal is observed, leading to an upper limit on the total production cross-section of same-sign top-quark pairs of 1.6 fb at 95% confidence level. Corresponding limits on the three Wilson coefficients associated with the O-tu((1)), O-Qu((1)), and O-Qu((8)) operators in the Standard Model Effective Field Theory framework are derived

XMM/HST monitoring of the ultra-soft highly accreting narrow-line Seyfert 1 RBS 1332

Ultra-soft narrow-line Seyfert 1s (US-NLSy 1s) are a poorly observed class of active galactic nuclei characterised by significant flux changes and an extreme soft X-ray excess. This peculiar spectral shape represents a golden opportunity to test whether the standard framework commonly adopted for modelling local AGNs is still valid. We thus present the results of the joint XMM-Newton and HST monitoring campaign of the highly accreting US-NLSy RBS 1332. The optical-to-UV spectrum of RBS 1332 exhibits evidence for both a stratified narrow-line region and an ionised outflow that produces absorption troughs over a wide range of velocities (from ∼–1500 km s−1 to ∼1700 km s−1) in several high-ionisation transitions (Lyα, N v, C iv). From a spectroscopic point of view, the optical/UV/FUV/X-ray emission of this source is due to the superposition of three distinct components that are best modelled in the context of the two-coronae framework in which the radiation of RBS 1332 can be ascribed to a standard outer disc, a warm Comptonisation region, and a soft coronal continuum. The present dataset is not compatible with a pure relativistic reflection scenario. Finally, the adoption of the novel model reXcor allowed us to determine that the soft X-ray excess in RBS 1332 is dominated by the emission of the optically thick and warm Comptonising medium, and only a marginal contribution is expected from relativistic reflection from a lamppost-like corona

Introduzione

introduzione/presentazione dei risultati delle ricerche dal titolo "Valorizzazione del patrimonio del borgo storico di Tolfa con particolare attenzione ai palazzi storici e agli spazi pubblici" contenuti nel volume "Strategie per la valorizzazione del paesaggio storico di Tolfa"Introduction and presentation of the results of the research entitled "EValorizzazione del patrimonio del borgo storico di Tolfa con particolare attenzione ai palazzi storici e agli spazi pubblici" included in the volume "Strategie per la valorizzazione del paesaggio storico di Tolfa