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Microbial life in Arctic pack ice: Prospects for the Tara Polaris expeditions
No full textInternational audienceSea ice, unlike freshwater ice, hosts abundant microbial life, thanks to the presence of liquid water inclusions encased within the ice matrix. The forthcoming Tara Polaris Expeditions (TPE), which will document drifting Arctic pack ice repeatedly over multiple years, together offer an unprecedented opportunity to advance understanding of the sea-ice microbiome -its diversity, variations, and ecological roles. In this contribution, we consider the current state of knowledge, identify key research gaps, and outline the potential for progress enabled by TPE. We envision the emergence of new insights into the seasonal evolution of microbial life, resolved at the floe (kilometric) scale, in relation to the evolution of the sea-ice environment -its morphology, light, temperature, and liquid water distribution and properties. Large potential lies in the characterization of diverse microhabitats across the central Arctic Ocean, associated with brine inclusions, pressure ridge cavities, and melt ponds. A major goal will be to document biological processes that remain poorly understood -colonization, diversity, functioning, interactions, and evolutionary dynamics -and that could benefit from the application of newly developed techniques. We argue that TPE is particularly timely, as the loss of multi-year ice may soon constrain opportunities to study life in this rapidly changing habitat
Model-independent ZH production cross section at FCC-ee
No full textInternational audienceThis paper presents prospects for a model-independent measurement of the production cross section at the FCC-ee using the recoil-mass technique at center-of-mass energies of and GeV. The analysis considers the muon, electron, and hadronic decay modes of the associated boson. Event selections rely primarily on the kinematic properties of the reconstructed decay products, ensuring maximal independence from specific Higgs boson decay modes, while multivariate techniques are employed to further enhance sensitivity. Statistical interpretations of the individual final states yield relative precisions of for the combined leptonic channels and for the hadronic channel at GeV with an integrated luminosity of ab. Their full statistical combination leads to total uncertainties of at GeV and at GeV with ab. Dedicated statistical tests demonstrate model independence at the level of the obtained precision. This study presents, for the first time, a consistent and combined analysis of the leptonic and hadronic final states, achieving the most precise projected determination of the production cross section at future lepton colliders, with model independence demonstrated within the statistical precision
Search for ttbar resonances in final states with exactly one or two leptons using 140 fb of pp collision data at TeV with the ATLAS experiment
No full textInternational audienceA search for heavy spin-1 and spin-2 resonances decaying into a top-antitop-quark pair has been performed with 140 fb of proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider at a centre-of-mass energy of TeV. Final states with either exactly one electron or muon, or exactly two leptons (, or ), large missing transverse momentum, and two jets, at least one of which must be identified as likely containing a b-hadron decay, are considered. The search targets resonances with both narrow and broad widths relative to the detector resolution, and with masses in the range of 0.4-5.0 TeV. No significant deviation from the Standard Model prediction is observed. Exclusion limits are set on the production cross-section times branching ratio for hypothetical bosons, Kaluza-Klein gravitons, and Kaluza-Klein gluons that decay into top-quark pairs
A comprehensive analysis of the decay
No full textInternational audienceAn analysis of the decay is presented using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 8.4 fb. The full set of -averaged and -asymmetric angular observables is determined in bins of the invariant mass squared of the dimuon system, as well as the branching fraction relative to the decay. For the first time, the full set of observables pertaining to the S-wave contribution to the final state are presented and consideration is given to effects arising from the mass of the muons. The measurements of the -averaged observables and the branching fractions continue to exhibit the pattern of tensions with the Standard Model predictions that have been seen in previous analyses that use part of the dataset considered in this study. The extracted -asymmetry observables show no significant deviations from zero
The Simons Observatory: forecasted constraints on primordial gravitational waves with the expanded array of Small Aperture Telescopes
No full textInternational audienceWe present updated forecasts for the scientific performance of the degree-scale (0.5 deg FWHM at 93 GHz), deep-field survey to be conducted by the Simons Observatory (SO). By 2027, the SO Small Aperture Telescope (SAT) complement will be doubled from three to six telescopes, including a doubling of the detector count in the 93 GHz and 145 GHz channels to 48,160 detectors. Combined with a planned extension of the survey duration to 2035, this expansion will significantly enhance SO's search for a -mode signal in the polarisation of the cosmic microwave background, a potential signature of gravitational waves produced in the very early Universe. Assuming a noise model with knee multipole and a moderately complex model for Galactic foregrounds, we forecast a (or 68% confidence level) constraint on the tensor-to-scalar ratio of , assuming no primordial -modes are present. This forecast assumes that 70% of the -mode lensing signal can ultimately be removed using high resolution observations from the SO Large Aperture Telescope (LAT) and overlapping large-scale structure surveys. For more optimistic assumptions regarding foregrounds and noise, and assuming the same level of delensing, this forecast constraint improves to . These forecasts represent a major improvement in SO's constraining power, being a factor of around 2.5 times better than what could be achieved with the originally planned campaign, which assumed the existing three SATs would conduct a five-year survey
Microalgae, sunlight, and starch: low cell concentration is optimal for outdoor production under nutrient stress
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Coupled EBSD/TKD/APT study of segregation induced by irradiation in a Fe-13at.%Cr model alloy through different grain boundaries type
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Performance of the front-end electronics of the CMS electromagnetic calorimeter barrel for the High-Luminosity LHC
No full textInternational audienceThe performance of the CMS electromagnetic calorimeter upgraded readout electronics, developed for the High-Luminosity phase of the LHC, is discussed. Data collected in two beam test campaigns conducted in 2018 and 2021 at the H4 and H2 beam lines of the CERN SPS are analyzed. Time and energy resolutions are measured on a matrix of lead tungstate crystals equipped with prototypes of the new front end readout electronics, using electron and pion beams of energies spanning from 25 to 250 GeV. In both campaigns the constant term of the energy resolution is measured to be better than 0.6% and the time resolution for electrons with energies above 50 GeV is measured to be better than 30 ps, fulfilling the design requirements
MIL-101(Cr)-SO3H fonctionnalisé au bleu de Prusse pour la capture des ions Cs+ dans la gestion des eaux contaminées.
No full textInternational audienceThis study investigates the property of Metal-Organic Frameworks (MOFs) grafted with Prussian blue analogs (PBA) for the efficient removal of Cs+ ions from aqueous solutions. MIL-101(Cr)-SO3H-PBA material was synthesized using a two-step process: hydrothermal reaction between monosodium 2-sulfoterephthalic acid (BDC-SO3Na) and chromium oxide (CrO3) to produce MIL-101(Cr)-SO3H, followed by grafting with CuK2[Fe(CN)6] (PBA). Both materials were characterized using XRD, IR, N2 sorption and Raman spectroscopy. The results confirmed the conservation of MOF porosity after functionalization and the successful incorporation of PBA. Batch adsorption experiments were conducted to evaluate Cs+ removal performance of the adsorbents. The study examined contact time (up to 1440 min), pH (2, 7 and 11), initial Cs+ concentration (from 9 ppb to 1800 ppm) and competing ions. The resistance of the porous solids under drastic conditions involving gamma radiation (from 0.5 MGy up to10 MGy) was also investigated.MI-101(Cr)-SO3H-PBA exhibited a maximum Cs+ adsorption capacity of 242 mg.gMOF-1, compared to 161 mg.gMOF-1 for pristine MIL-101(Cr)-SO3H and showed high selectivity toward Cs+ in the presence of competing ions (Na+, K+, Mg2+, Ca2+, Sr2+). MI-101(Cr)-SO3H-PBA also demonstrates remarkable stability under radiation and alkaline conditions, maintaining 95% efficiency, whereas the performance of pristine MIL-101(Cr)-SO3H material decreased significantly (7.5-fold decrease).Cette étude examine la propriété des Metal-Organic Frameworks (MOF) greffés avec des analogues de bleu de Prusse (PBA) pour l'élimination efficace des ions Cs+ des solutions aqueuses. Le matériau MIL-101(Cr)-SO3H-PBA a été synthétisé en deux étapes : une réaction hydrothermale entre l'acide 2-sulfotéréphtalique monosodique (BDC-SO3Na) et l'oxyde de chrome (CrO3) pour produire le MIL-101(Cr)-SO3H, suivie d'un greffage avec du CuK2[Fe(CN)6] (PBA). Les deux matériaux ont été caractérisés par DRX, IR, sorption de N2 et spectroscopie Raman. Les résultats ont confirmé la conservation de la porosité du MOF après fonctionnalisation et l'incorporation réussie du PBA. Des expériences d'adsorption en mode batch ont été menées pour évaluer la performance des adsorbants en matière d'élimination du Cs+. L'étude a examiné le temps de contact (jusqu'à 1440 min), le pH (2, 7 et 11), la concentration initiale en Cs+ (de 9 ppb à 1800 ppm) et l'effet des ions compétiteurs. La résistance des solides poreux dans des conditions drastiques impliquant un rayonnement gamma (de 0,5 MGy jusqu'à 10 MGy) a également été étudiée.Le MIL-101(Cr)-SO3H-PBA a présenté une capacité d'adsorption maximale du Cs+ de 242 mg.gMOF-1, contre 161 mg.gMOF-1 pour le MIL-101(Cr)-SO3H non modifié, et a montré une sélectivité élevée pour le Cs+ en présence d'ions compétiteurs (Na+, K+, Mg2+, Ca2+, Sr2+). Le MIL-101(Cr)-SO3H-PBA a également démontré une stabilité remarquable sous rayonnement et en conditions alcalines, maintenant une efficacité de 95 %, tandis que la performance du matériau MIL-101(Cr)-SO3H non modifié a diminué de manière significative (une réduction de 7,5 fois)
