IF - Artigos publicados em periódicos

URI Permanente para esta coleçãohttp://200.137.215.59//handle/ri/1359

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Crystal-field effects on dipole moments and static first hyperpolarizability in noncentrosymmetric ionic organic crystals
(2026) Leão, Salviano de Araújo; Jesus, Augusto César de; Castro, Marcos Antônio de; Fonseca, Tertius Lima da
Understanding how crystal fields modify local nonlinear optical responses is essential for the rational design of acentric ionic organic crystals. Here, we investigate a structurally diverse set of noncentrosymmetric push−pull ionic crystals, including classical stilbazolium benchmarks and 6MNEP-related GUR/GUS crystals identified by their CCDC refcodes, to evaluate how electrostatic embedding affects the dipole moment and total static first hyperpolarizability (βtot) of asymmetric units. A selfconsistent electrostatic-embedding approach combined with density functional theory (DFT) and time-dependent-DFT (TDDFT) calculations was used to compare isolated and in-crystal ionpair responses within a consistent local-descriptor framework. The results show that the crystal field does not act as a uniform amplifier or suppressor of βtot. Instead, its effect depends on the local electrostatic environment, ion-pair organization, and tensor-component balance. Classical stilbazolium salts generally retain large embedded hyperpolarizabilities, with DAPSH, DSTMS, DSCHS, and DSNS-1 among the most responsive systems. In contrast, most 6MNEP-related GUR/GUS crystals show substantial attenuation of βtot upon embedding, while DSCHS, DSNS-1, and the structurally related MBST salt display enhanced embedded responses relative to their isolated counterparts. These results indicate that favorable local crystal-field alignment and contact patterns can reinforce, rather than suppress, the molecular response in selected cases. Overall, explicit crystal embedding provides a useful comparative strategy for analyzing how ion-pair composition and lattice organization modulate local dipolar and hyperpolarizability descriptors in ionic organic Organic nonlinear optical (NLO) crystals
H.E.S.S. observations of composite Seyfert–starburst galaxies
(2026) Acharyya, Atreya; Aharonian, Felix; Achkar, Halim El; Backes, Michael; Martins, Victor Barbosa; Batzofin, Rowan; Becherini, Yvonne; Berge, David; Boettcher, Markus; Boisson, Catherine
Context. Composite galaxies that contain both Seyfert and starburst components may produce very high-energy (VHE; >100 GeV) γ-ray emission at a wide range of spatial scales, from a few Schwarzschild radii of a supermassive black hole (SMBH; RS = 10−6 pc for MSMBH = 107 M ) to dimensions of kiloparsec-size jet-driven outflows. In addition to supernova remnants, various sources have been suggested to explain data collected on composite galaxies, including multi-messenger neutrino and ultra-high-energy cosmic-ray data. Aims. The closest composite Seyfert–starburst galaxies (NGC 1068, the Circinus galaxy, and NGC 4945) are observed with the High Energy Stereoscopic System (H.E.S.S.) to provide constraints on cosmic-ray populations in these systems. Methods. Data obtained in H.E.S.S. observations have been analyzed to search for VHE γ-ray counterparts to the GeV γ-ray signals detected with Fermi-LAT and for potential spectral components in the VHE range. Results. No significant signals have been found in these H.E.S.S. data. Upper limits on the VHE γ-ray fluxes were applied to constrain theoretical models involving different spectral components.
Chasing gamma-ray signals from binary neutron star coalescences with the cherenkov telescope array: prospects and observing strategies
(2026) Abe, Shotaro; Abhir, J.; Abhishek, A.; Acero, F.; Acharyya, Atreya; Adam, R.; Aguasca-Cabot, A.; Agudo, I.; Albanese, I.; Alfaro, J.; Martins, Victor Barbosa
The detection of gravitational waves (GWs) from a binary neutron star (BNS) merger by Advanced LIGO and Advanced Virgo (GW170817), together with its electromagnetic counterpart, the short gamma-ray burst GRB 170817A, heralded the birth of multimessenger astronomy. The detection of TeV emission from GRBs motivates follow-up observations with the Cherenkov Telescope Array Observatory (CTAO), which is ideal for detecting such signals due to its unprecedented sensitivity, rapid response, and wide-field survey capabilities. The aim of this work is to evaluate GeV–TeV GW follow-up strategies for CTAO using a multistep simulation pipeline and to estimate the expected rate of joint GW–GRB detections during observing run O5. Using a simulated sample of BNS systems with corresponding GW detections, gamma-ray emission is simulated through phenomenological prescriptions based on the observed population of short GRBs, including off-axis jet scenarios. CTAO observations are simulated to account for instrument response, sky tiling strategies, integration times, and varying observing conditions. Strategies with variable and constant integration times are investigated. We find that, via an optimized follow-up strategy, about 5% of simulated GW-associated short GRBs produce GeV–TeV radiation detectable by CTAO. Detectability is strongly influenced by the jet opening angle and viewing angle, suggesting that even rough estimates of the viewing angle in GW alerts could enhance targeting. This framework motivates future follow-ups of GW-detectable events, including neutron star–black hole mergers, and further supports the development of advanced strategies incorporating galaxy distributions and synergies with future detectors such as the Einstein Telescope.
Solvent polarity as a selective modulator of the first hyperpolarizability in para-substituted azo-carbazole dyes
(2026) Ferreira, Murilo Benedito Martins; Georg, Herbert de Castro; Castro, Marcos Antônio de; Fonseca, Tertius Lima da
Azo−carbazole monolithic dyes are promising candidates for photonic and optoelectronic applications due to their tunable push−pull character and strong nonlinear optical response. Here, we present a systematic density functional theory (DFT)/time-dependent DFT investigation of seven para-substituted azo−carbazoles (AmACzE, MACzE, HACzE, FACzE, AACzE, CACzE, and NACzE), aimed at elucidating how solvent polarity modulates the first hyperpolarizability (βHRS) using longrange corrected hybrid functionals combined with a polarizable continuum model. Our results demonstrate that solvent polarity does not act as a universal enhancer of nonlinear response, but rather as a selective amplifier whose efficiency is governed by the intrinsic charge-transfer capability of the chromophore. Electron-withdrawing substituents (F, COCH3, CN, and NO2) establish a well-defined push−pull axis, leading to large ground-toexcited-state dipole moment variation (Δμ) and high βHRS values, reaching up to 115 × 10−30 esu for NACzE in water. In contrast, donor-substituted derivatives (NH2, OCH3, and OH) exhibit enhanced local polarization but a limited Δμ, indicating a predominantly localized excited-state character, even in highly polar environments. By correlating βHRS with Δμ within a two-state framework, this work establishes Δμ as a quantitative descriptor controlling both the magnitude and the solvent sensitivity of the nonlinear response. These findings provide clear design guidelines for azo−carbazole-based NLO materials, demonstrating that efficient second-order response arises from the synergistic combination of strong acceptor substitution and polar environments, while also defining the intrinsic limits of solvent-induced enhancement
Science with a large field-of-view polarization survey: the Large Array Survey Telescope Polarization Node (LAST-P)
(2026) Martins, Victor Barbosa; Jordana-Mitjans, Núria; Garrappa, Simone; Franckowiak, Anna; Ofek, Eran; Ben-Ami, Sagi; Borowska-Naguszewska, Jowita; Ramazani, Vandad Fallah; Konno, Ruslan; Küsters, Daniel; Parsons, Robert Daniel
Optical polarimetry provides information on the geometry of the emitting region, the magnetic field configuration and the properties of dust in astrophysical sources. Current state-of-the-art instruments typically have a small field of view (FoV), which poses a challenge for conducting wide surveys. We propose the construction of the Large Array Survey Telescope Polarization Node (LAST-P), a wide-field array of optical polarimeters. LAST-P is designed for high-cadence (≲1 day) polarization monitoring of numerous astrophysical transients, such as the early phases of gamma-ray bursts, supernovae, and novae. Furthermore, LAST-P will facilitate the creation of extensive polarization catalogs for X-ray binaries and white dwarfs, alongside a large FoV study of the interstellar medium. In survey mode, LAST-P will cover a FoV of 88.8 deg2. With a 15 ×1 minutes exposure, the instrument will be capable of measuring polarization of sources as faint as Gaia Bp-magnitude ∼20.9. The precision on the linear polarization degree will reach 0.7%, 1.5%, and 3.5% for sources with magnitudes 17, 18, and 19, respectively, for a seeing of 2.7, air mass of about 1 for observations in dark locations. We propose three distinct non-simultaneous survey strategies, among them an active galactic nuclei (AGN) strategy for long-term monitoring of ∼200 AGN with <1 day cadence. In this paper, we present the predicted sensitivity of the instrument and outline the various science cases it is designed to explore.
The second H.E.S.S. gamma-ray burst catalogue: 15 years of observations with the H.E.S.S. telescopes
(2026) Acharyya, Atreya; Aharonian, Felix; Arcaro, Cornelia Hanna Esther; Achkar, Halim El; Backes, Michael; Martins, Victor Barbosa; Batzofin, Rowan; Becherini, Yvonne; Berge, David; Bernlöhr, Konrad
Context. Recent observational efforts using imaging atmospheric Cherenkov telescopes (IACTs) have led to firm detections of very-high-energy (VHE) signals from bright gamma-ray bursts (GRBs), often at moderate redshifts. Aims. This work presents 15 years of H.E.S.S. GRB observations and examines their implications through population comparisons and selected modelling cases. Methods. GRBs are a key science target of the High Energy Stereoscopic System (H.E.S.S.). With a low-energy threshold (.100 GeV) and rapid repointing capabilities, H.E.S.S. can begin follow-up observations within tens of seconds after a GRB trigger, covering the late prompt or early afterglow phases. Results. We report GRB follow-up observations with H.E.S.S. from 2004 to 2019, which resulted in no significant VHE signals (aside from the detections of GRB 180720B and GRB 190829A). The resulting upper limits comprise the largest set available for GRBs at VHE. Conclusions. A subset of bursts with favourable conditions were selected for X-ray analysis and emission modelling. Population studies were performed to compare detected and non-detected GRBs. The results indicate that VHE-detected GRBs are not a distinct population, but tend to feature luminous X-ray emission and favourable redshift and observing conditions. This highlights the potential of next-generation IACTs such as the Cherenkov Telescope Array Observatory (CTAO), whose lower energy threshold will enhance the detection of fainter and more distant GRBs.
Identification of low-energy kaons in the ProtoDUNE-SP detector
(2026) Abbaslu, Saeed; Alrahman, Fatima Abd; Abud, Adam Abed; Acciarri, Roberto; Accorsi, L. P.; Acero, M. A.; Adames, Marcio Rostirolla; Adamov, George; Adamowski, Mark; Gomes, Ricardo Avelino
The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment with a rich physics program that includes searches for the hypothetical phenomenon of proton decay. Utilizing liquid-argon time-projection chamber technology, DUNE is expected to achieve world-leading sensitivity in the proton decay channels that involve charged kaons in their final states. The first DUNE demonstrator, ProtoDUNE Single-Phase, was a 0.77 kt detector that operated from 2018 to 2020 at the CERN Neutrino Platform, exposed to a mixed hadron and electron test-beam with momenta ranging from 0.3 to 7 GeV/c. We present a selection of low-energy kaons among the secondary particles produced in hadronic reactions, using data from the 6 and 7 GeV/c beam runs. The selection efficiency is 1% and the sample purity 92%. The initial energies of the selected kaon candidates encompass the expected energy range of kaons originating from proton decay events in DUNE (below ∼200 MeV). In addition, we demonstrate the capability of this detector technology to discriminate between kaons and other particles such as protons and muons, and provide a comprehensive description of their energy loss in liquid argon, which shows good agreement with the simulation. These results pave the way for future proton decay searches at DUNE.
Luminescence lifetime up to microseconds in new coordination compounds with aminopyrazine and acetate
(2027) Alvarenga, Meiry Edivirges; Santana, Ricardo Costa de; Maia, Lauro June Queiroz; Dutra, Bárbara Júlia Gonçalves; Guimarães, Freddy Fernandes; Martins, Felipe Terra
Aminopyrazine (ampyz) and cadmium acetate assemble into a potent blue light emitting one-dimensional co- ordination polymer upon UV excitation. Here we were devoted to the replacement of cadmium in this optical material given its environmental and human health drawbacks. Three new ampyz-based coordination com- pounds were prepared and elucidated structurally, and had their light emission investigated upon UV excitation. The dihydrate crystal form of the discrete compounds [Co(ampyz)2(AcO)2(H2O)2] and [Ni(ampyz)2(A- cO)2(H2O)2] reveal to be isostructural themselves and to Zn2+ and Mn2+ versions thereof. Compound [Ag (ampyz)(AcO)]n(H2O)n assembles into polymeric one-dimensional coordination chains which are strongly bonded to each other through π...π interactions, hydrogen bonding and intermetallic bonds. Despite of their negligible emission power, their found luminescence lifetimes presented values up to 6 times greater than the previously reported parent complex, which can be correlated to the presence and strength of π...π stacking in- teractions. The Ag+ compound has the shortest π...π interactions measuring 3.415 Å, with the emission lifetime in the μs order. However, these intermolecular contacts seem be responsible to quench the emission power together with intrinsic electronic features probed by TD-DFT. The electronic transitions responsible for UV excitation exhibit low oscillator strengths due to the orthogonality of the donor and acceptor orbitals, receiving significant metal d contribution besides enrolment of single-coordinated acetate ligand.
Merging multidimensional equations of state of strongly interacting matter via a statistical mixture
(2026) Yang, Yumu; Garella, Prachi; Khan, Musa Rahim; Restrepo Medina, Tulio Eduardo; Grefa, Joaquin; Jahan, Johannes; Ratti, Claudia; Rougemont, Rômulo Cesar
We introduce a general method to merge multidimensional equations of state (EoSs) by combining them in a two-fluid equilibrium statistical mixture in the grand canonical ensemble. The merged grand potential density 𝜔 is built directly from the input EoSs and the fluid fractions are fixed by minimizing 𝜔 at fixed temperature 𝑇 and baryon chemical potential 𝜇𝐵. Thermodynamic consistency and stability are guaranteed, as all thermodynamic quantities are consistently derived from a single merged grand potential 𝜔⁡(𝑇,𝜇𝐵) with the correct convexity properties. Our method can accommodate a first-order phase transition and a critical endpoint with mean-field critical exponents. We use this method to merge a van der Waals Hadron–Resonance–Gas EoS with a holographic Einstein–Maxwell–Dilaton EoS that has a critical point and a first-order line. The result is a single EoS, spanning hadronic and deconfined matter over a broad range in (𝑇,𝜇𝐵), which can be readily used in heavy-ion hydrodynamic simulations. Our merging method can be generalized to consider a higher-dimensional phase diagram (e.g., by considering more chemical potentials) and more than two input EoSs.
Explanation of the seasonal variation of cosmic multiple muon events observed with the NOvA Near Detector
(2026) Abubakar, Saleh; Acero, M. A.; Acharya, Bishnu; Adamson, Philip; Anfimov, Nikolay Vladimirovich; Antoshkina, Tatiana; Arrieta Díaz, Enrique; Asquith, Lily; Aurisano, Adam J.; Back, A.; Gomes, Ricardo Avelino
The flux of cosmic ray muons at the Earth’s surface exhibits seasonal variations due to changes in the temperature of the atmosphere affecting the production and decay of mesons in the upper atmosphere. Using 1473 live days of data collected by the NuMI Off-axis 𝜈𝑒 Appearance (NOvA) Near Detector during 2018–2022, we studied the seasonal pattern in the multiple-muon event rate. The data confirm an anticorrelation between the multiple-muon event rate and effective atmospheric temperature, consistent across all the years of data. Previous analyses from MINOS and NOvA saw a similar anticorrelation but did not include an explanation. We find that this anticorrelation is driven by altitude–geometry effects as the average muon production height changes with the season. This has been studied with a CORSIKA cosmic ray simulation package by varying atmospheric parameters, and provides an explanation to a longstanding discrepancy between the seasonal phases of single and multiple-muon events.
Precision measurement of neutrino oscillation parameters with 10 years of data from the NOvA experiment
(2026) Abubakar, Saleh; Acero, M. A.; Acharya, Bishnu; Adamson, Philip; Anfimov, Nikolay Vladimirovich; Antoshkina, Tatiana; Arrieta Díaz, Enrique; Asquith, Lily; Aurisano, Adam J.; Azevedo, Daniel Araújo de; Gomes, Ricardo Avelino
This Letter reports measurements of muon-neutrino disappearance and electron-neutrino appearance and the corresponding antineutrino processes between the two NOvA detectors in the NuMI neutrino beam. These measurements use a dataset with double the neutrino mode beam exposure that was previously analyzed, along with improved simulation and analysis techniques. A joint fit to these samples in the three-flavor paradigm results in the most precise single-experiment constraint on the atmospheric neutrino mass splitting, Δ⁢𝑚2 32=2.43⁢1+0.036 −0.034⁢(−2.47⁢9+0.036 −0.036)×10−3 eV2 if the mass ordering is normal (inverted). In both orderings, a region close to maximal mixing with sin2⁡𝜃23=0.5⁢5+0.02 −0.06 is preferred. The NOvA data show a mild preference for the normal mass ordering with a Bayes factor of 2.4 (corresponding to 70% of the posterior probability), indicating that the normal ordering is 2.4 times more probable than the inverted ordering. When incorporating a 2D Δ⁢𝑚2 32−sin2⁡2⁢𝜃13 constraint based on Daya Bay data, this preference strengthens to a Bayes factor of 6.6 (87%).
Luminescence thermometry of a NdIII and NdIII/YbIII imidazole derived-based MOFs: thermally enhanced ytterbium emission
(2026) Farías Carreño, Patricia; Gálvez Guajardo, Sebastián Horacio; Gil Sánchez, Yolimar; Santana, Ricardo Costa de; Spodine, Evgenia; Carneiro Neto, Albano; Fuentealba Castro, Pablo Andrés
Lanthanides' luminescent thermometry operating in biological windows highlights its promising applications, constantly improving performances, and interesting new findings. This work presents two MOFs, a homometallic sample based on neodymium (1) and a heterometallic one including ytterbium cations (2) as thermometers in the physiological temperature range, operating in biological windows (BWs). These materials were developed with the aim of understanding their thermometric performance and to gain deep knowledge into the energy transfer between the mentioned cations. The homometallic sample achieved a maximum relative sensitivity (Sr) of 0.59%K-1 at 20°C by using the luminescence intensity ratio (LIR) of the two components that contribute to the main emission band ca. 1060 nm, which is associated with the 4F3/2 → 4F11/2 transition. In the case of the heterometallic sample, interestingly, there is an increase in the intensity of the ytterbium cation emission as the temperature increases. This behavior was rationalized by means of theoretical calculations and matches other examples from the literature. The YbIII/NdIII intensity ratio achieves a maximum Sr 0.53%K-1 at 20°C.
Charge readout electronics for the DUNE horizontal drift far detector: design and performance in ProtoDUNE-HD
(2026) Abbaslu, Saeed; Alrahman, Fatima Abd; Abud, Adam Abed; Acciarri, Roberto; Accorsi , L. P.; Acero, M. A.; Adame, Marcio Rostirolla; Adamov, George; Adamowski, Mark; Gomes, Ricardo Avelino
DUNE (Deep Underground Neutrino Experiment) is a long-baseline neutrino oscillation experiment currently under construction, whose far detectors will be the largest liquid argon time projection chambers ever built. This detector design calls for custom-built cryogenic front-end electronics to meet its performance requirements. This paper describes the charge readout electronics that will be used in the DUNE horizontal drift (HD) far detector and presents performance results using data from the ProtoDUNE-HD detector, a 770 ton liquid argon time projection chamber operated at the CERN Neutrino Platform in 2024 that served as the final prototype of the DUNE HD design.
Electronic and optical properties of ultra-wide gap two-dimensional germanium dioxide
(2026) Reis, Rafael Franco Ribeiro; Araújo, Gabriel Elyas Gama; Kuritza, Danilo de Paula; Sousa, José Eduardo Padilha de; Dias, Alexandre Cavalheiro; Rosa, Andréia Luisa da; Pontes, Renato Borges
We employ first principles density-functional theory and the Bethe-Salpeter equation (BSE) in the framework of tight-binding based maximally localized Wannier functions model to investigate the electronic and optical properties of free-standing two-dimensional (2D) germanium dioxide phases. All investigated 2D GeO2polymorphs exhibit ultra-wide band gaps (3.6-5.3 eV) and strong excitonic effects, with valence bands tunable under strain. These features allow the design of materials with ultra large electronic gaps in low-dimensional systems, making these materials promising for devices operation at higher voltages and temperatures than conventional semiconductor materials.
Tunable Nd3+ dimer luminescent molecular thermometer via Stark sublevels
(2026) Gil Sánchez, Yolimar; Corredoira-Vázquez, Julio; Santana, Ricardo Costa de; Brites, Carlos António Delgado Sousa; Carlos, Luís António Ferreira Martins Dias; Spodine, Evgenia; Aravena, Daniel; Fuentealba Castro, Pablo Andrés
The near-infrared (NIR) luminescence thermometry performance of the Nd-based dimer {[Nd(acac)3]2(μ- bpm)} (Nd2) (where acac− denotes acetylacetonate and bpm is 2,2’-bipyrimidine) was investigated under both ligand- and metal-centered excitation. To resolve the Stark components of the 4F3/2 → 4 I11/2 tran-sition, ab initio electronic structure calculations were performed. The opposite temperature dependences of the lower- and higher-energy components of the 4F3/2 level were used as a thermometric parameter, expressed through the luminescence intensity ratio (LIR). Under ligand-centered excitation at 370 nm, Nd2 exhibited a maximum relative sensitivity (Sm) of 2.1% K−1 at 85 K, across the 85–285 K range, demon- strating excellent thermal performance at low temperatures. Considering the relevance of NIR-to-NIR emitters for biomedical applications, the thermometric response was also evaluated under metal-cen- tered excitation at 804 nm within the physiological range (294–332 K). In this case, an unprecedented Sm value of 2.5% K−1 at 294 K was obtained, setting a new benchmark for Nd-based molecular thermometers and highlighting its potential for biological temperature sensing. Overall, Nd2 operates as a versatile lumi- nescent molecular thermometer whose thermal response can be tuned simply by selecting the excitation wavelength (UV or NIR), enabling adaptable, application-specific thermometric behavior.
Triple-readout luminescence thermometry in a heterodinuclear Yb–Er complex and performance comparison with the homodinuclear analogues
(2026) Gil Sánchez, Yolimar; Corredoira-Vázquez, Julio; Santana, Ricardo Costa de; Vega Carvallo, Andrés; Carneiro Neto, Albano; Aravena, Daniel; Spodine, Evgenia; Brites, Carlos António Delgado Sousa; Carlos, Luís António Ferreira Martins Dias; Fuentealba Castro, Pablo Andrés
This work reports the thermometric properties of a heterodinuclear Yb–Er complex, [{Yb(tta)3}(µ2-bpm){Er(tta)3}] (1) (tta− = thenoyltrifluoroacetonate and bpm = 2,2'-bipyrimidine), together with the corresponding homodinuclear analogues [{Ln(tta)3}2(µ2-bpm)] (Ln = Yb(2), Er(3)). Under 394 nm excitation, complex 1 enables temperature sensing over the 12–310 K range using three luminescence intensity ratio (LIR) readouts based on Yb3+ and Er3+ emissions, while complexes 2 and 3 provide single-ion-based thermometric responses. Among these, the Yb3+ (2F5/2 → 2F7/2)/Er3+(4I13/2 → 4I15/2) LIR yields the highest relative thermal sensitivity for 1, with a maximum value (Sm) of 2.5% K−1 at 12 K, and 1.0% K−1 at 310 K. Importantly, 1 represents the first heterodinuclear Yb–Er complex exhibiting thermometric properties and, more remarkably, enabling temperature sensing through three distinct LIR-based readouts. The Yb-only complex 2 exhibits Sm = 3.6% K−1 at 110 K, among the highest reported for Yb3+ molecular thermometers, while Er-based readouts in 1 and 3 provide moderate sensitivities at higher temperatures. Comparative analysis highlights the role of Yb3+ → Er3+ energy transfer in modulating the thermometric behaviour of the heterodinuclear complex. Theoretical calculations support the presence of metal–metal and ligand-mediated energy-transfer pathways, which contribute to the observed temperature-dependent luminescence response.
Experimental investigation of the role of spatial correlations in optical integration with heralded single photons
(2026) Silva, Lucas Marques Fagundes; Pimenta, Raphael César de Souza; Paula, Murilo Henrique Magiotto de; Gomes, Rafael de Morais; Duzzioni, Eduardo Inácio; Araújo, Renné Luiz Câmara Medeiros de; Ribeiro, Paulo Henrique Souto
In this work, we demonstrate optical integration using heralded single photons and explore the influence of spatial correlations between photons on this process. Specifically, we experimentally harness the transverse spatial degrees of freedom of light within an optical processing framework based on heralded single photons. The integration is performed over binary phase patterns encoded via a phase-only spatial light modulator, with polarization serving as an auxiliary degree of freedom. Our findings reveal a distinct contrast in how spatial correlations affect image analysis: spatially uncorrelated photons are more effective at capturing the global features of an image encoded in the modulator, whereas spatially correlated photons exhibit enhanced sensitivity to local image details. Importantly, the optical integration scheme presented here bears a strong conceptual and operational resemblance to the DQC1 (Deterministic Quantum Computation with One Qubit) model. This connection underscores the potential of our approach for quantum-enhanced information processing, even in regimes where entanglement is minimal or absent.
Reconstruction of atmospheric neutrinos in DUNE’s horizontal-drift far-detector module
(2026) Abbaslu, Saeed; Alrahman, Fatima Abd; Abud, Adam Abed; Acciarri, Roberto; Accorsi, L. P.; Acero, M. A.; Adame, Marcio Rostirolla; Adamov, George; Adamowski, Mark; Adriano, Cris; Gomes, Ricardo Avelino
This paper reports on the capabilities in reconstructing and identifying atmospheric neutrino interactions in one of the Deep Underground Neutrino Experiment’s (DUNE) far detector modules, a liquid argon time projection chamber (LArTPC) with horizontal drift (FD-HD) of ionization electrons. The reconstruction is based upon theworkflow developed for DUNE’s long-baseline oscillation analysis, with some necessary machine-learning models’ retraining and the addition of features relevant only to atmospheric neutrinos such as the neutrino direction reconstruction. Where relevant, the impact of the detection of the charged particles of the hadronic system is emphasized, and comparisons are carried out between the case when lepton-only information is considered in the reconstruction (as is the case for many neutrino oscillation experiments), versus when all particles identified in the LArTPC were included. Three neutrino direction reconstruction methods have been developed and studied for the atmospheric analyses: using lepton-only information, using all reconstructed particles, and using only correlations from reconstructed hits. The results indicate that incorporatingmore than just lepton information significantly improves the resolution of both neutrino direction and energy reconstruction. The angle reconstruction algorithms developed in this work result in no strong dependence on particle direction for reconstruction efficiencies or neutrino flavor identification. This comprehensive review of the reconstruction of atmospheric neutrinos in DUNE’s FD-HD LArTPC is the first step towards developing a first neutrino oscillation sensitivity analysis, which will ready DUNE for its first measurements.
Operation of a modular 3D-pixelated liquid argon time-projection chamber in a neutrino beam
(2026) Abbaslu, Saeed; Abud, Adam Abed; Acciarri, Roberto; Acero, M. A.; Adames, Márcio Rostirolla Adames; Adamov, George; Adamowski, Mark; Adriano , Cris; Akbar, F.; Gomes, Ricardo Avelino
The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events.
Unraveling the photophysical processes in supramolecular tetraruthenated thienyl porphyrins
(2026) Leite, Taíse Helena Oliveira; Souza, Lucas Soares; Pereira, George Bueno Santana; Rocha, Fillipe Vieira; Batista, Alzir Azevedo; Gonçalves, Pablo José; Barbosa Neto, Newton Martins; Lopes, Jefferson Marcio Sanches
In the present work, we investigated two supramolecular tetraruthenated porphyrins. The first originates from the decoration of the thienyl sites of a meso-tetra-thienyl free base (TThP) porphyrin with the RuCl2(dppb)(5,5′-Mebipy) ruthenium complex (named RuT) (yielding the sample TThP-RuT), whereas the second is a variant form in which besides accommodating the RuT moieties, the thienyl also undergoes methylation, resulting in the sample TThP(me)-RuT. The structure-dependent response of the photophysical processes was inspected through steady-state and time-resolved spectroscopies, revealing significant effects in the electronic spectra, vibronic progressions, fluorescence quantum yields, radiative (non-radiative) deactivation rate and excited-state lifetimes of the pristine porphyrin. The solvatochromic analysis also allowed exploring the variations introduced by the supramolecular constitution to the dipole moments of the porphyrin's singlet states. We also demonstrated the relationship between the samples´ structure and their singlet oxygen quantum yields. Finally, we confirmed that all samples are photostable under high pulsed laser fluences, supporting their potential practical uses in the future.

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