2,820 research outputs found

    Recent progress on isospin breaking corrections and their impact on the muon g-2 value

    Full text link
    We describe some recent results on isospin breaking corrections which are of relevance for predictions of the leading order hadronic contribution to the muon anomalous magnetic moment (amuhadLO) when using tau lepton data. When these corrections are applied to the new combined data on the pi^+pi^0 spectral function, the prediction for amuhadLO based on tau lepton data gets closer to the one obtained using e^+e^- data.Comment: 6 pages, 3 figures, Proceedings of the PhiPsi09 Workshop, Oct. 13-16, 2009, Beijing, China. Some typos corrected, and the FSR correction used in a previous work is added to Table

    Decline and Fall of the Standard Model?

    Get PDF
    Motivations for physics beyond the Standard Model are reviewed, with particular emphasis on supersymmetry at the TeV scale. Constraints on the minimal supersymmetric extension of the Standard Model with universal soft supersymmetry-breaking terms (CMSSM) are discussed. These are also combined with the supersymmetric interpretation of the anomalous magnetic moment of the muon. The prospects for observing supersymmetry at accelerators are reviewed using benchmark scenarios to focus the discussion. Prospects for other experiments are discussed, including the detection of cold dark matter, mu -> e gamma and related processes, as well as proton decay.Comment: Invited talk at 20th International Symposium on Lepton and Photon Interactions at High Energies, Rome, 2001, 16 pages LaTeX, 13 eps figures, uses special .cls file (included

    Substrate influence on the ferroelectric properties of PTCa thin films

    Get PDF
    [ES] Se han estudiado las propiedades ferroeléctricas de láminas delgadas de titanato de plomo modificado con calcio (Pb0.76Ca0.24)TiO3 (PTCa) preparadas vía sol gel mediante cristalizaciones sucesivas sobre tres tipos de substratos: (A) Pt / Ti / SiO2 / Si (100), (B) Ti / Pt / Ti / SiO2 / Si(100) y (C) Pt / TiO2 / SiO2 /Si (100). Los resultados de la caracterización ferroeléctrica muestran valores del coeficiente piroeléctrico espontáneo entorno a » 5 .10-9 C cm-2 K-1. La baja conmutabilidad de las laminas facilita la estabilización del valor del coeficiente piroeléctrico en el tiempo. Un tratamiento térmico posterior de recocido a 650ºC 1 hora produce cambios en las propiedades ferro-piezoeléctricas que se pueden asociar con modificaciones de la textura en las láminas.[EN] The ferroelectric properties of calcium modified lead titanate (Pb0.76Ca0.24)TiO3 (PTCa) thin films prepared by a sol - gel method with successive crystallisations on three different substrates (A) Pt / Ti / SiO2 / Si (100), (B) Ti / Pt / Ti / SiO2 / Si(100) y (C) Pt / TiO2 / SiO2 /Si (100), have been studied. The results of the ferroelectric characterisation show values of the spontaneous pyroelectric coefficient close to » 5 .10-9 C cm-2 K-1. The low switching properties favour the stabilisation in time of the pyroelectric coefficient value. Alatter annealing thermal treatment (650ºC 1h) produces changes in the ferro - piezoelectric properties that can be related with changes in the texture of the films.Este trabajo ha sido realizado mediante la financiación recibida de los proyectos MAT98 - 1068 (CICYT) y BRPR - CT98 - 0777 (BRITE EURAM de la U.E.).Peer reviewe

    Non-volatility of ferroelectric SBT thin fims, at 75ºC

    Get PDF
    [ES] El estudio de la no volatilidad de una memoria FeRAM de tantalato de bismuto y estroncio, SrBi2Ta2O9 (SBT) en condiciones reales de uso, requiere la caracterización ferroeléctrica del material en forma de lámina delgada a temperaturas por encima del ambiente. Para ello se han depositado láminas de SBT mediante un método sol-gel, sobre substratos de Pt/TiO2/SiO2/Si(100), seleccionándose condensadores de área 5.10-4 cm-2. Basándonos en las medidas de la variación de la polarización con el tiempo (retención) realizadas a temperatura ambiente y a 75ºC, analizamos la viabilidad del material como una FeRAM en condiciones reales de uso.[EN] The study of the non-volatility of Strontium bismuth tantalate SrBi2Ta2O9 (SBT) FeRAM memory, at real operating conditions, requires the ferroelectric characterisation of the material, as a thin film, above the room temperature.As a result, it has been deposited SBT films by the sol-gel method, onto Pt/TiO2/SiO2/Si (100) substrates, using capacitors of 5 x 10–4 cm-2 .In this work, we analysed the viability of this material as a FeRAM memory in real operating conditions, as a result of the variation of the polarisation measurements with time (retention), performed at room temperature and 75ºC.Este trabajo ha sido realizado con el apoyo del proyecto de la CICYT MAT98-1068.Peer reviewe

    Feasibility of (Pb, Ca)TiO3 thin films deposited on Pt/TiO2/SiO2/Si(100) for switching applications

    Get PDF
    [ES] Se han depositado láminas delgadas de (Pb,Ca)TiO3 sobre substratos de Pt/TiO2/SiO2/Si(100) por centrifugación, partiendo de soluciones sintetizadas por sol -gel. La concentración de las soluciones y el contenido de PbO se seleccionaron para minimizar las tensiones de las láminas cristalizadas y obtener la adecuada estequiometria. La cristalización mediante un calentamiento rápido (RTP), conduce a láminas con orientaciones preferentes [001]/[001], reducida capa interfacial ferroeléctrico-Pt y composición deseada. Los parámetros ferroeléctricos obtenidos muestran una mejora de las propiedades. Estas láminas presentan una fatiga y envejecimiento mucho más moderados que otros materiales alternativos depositados sobre substratos iguales, lo que permite considerar al método descrito como muy valioso para conseguir materiales susceptibles de emplear en aplicaciones de conmutación.[EN] (Pb,Ca)TiO3 ferroelectric thin films have been spin-coated on Pt/TiO2/SiO2/Si(100) substrates from sol-gel synthesized solutions. Selecting the solution concentrations and the excess of PbO content, stoichiometric composicion with reduced strains are obtained. Crystallization process by rapid thermal treatment (RTP) promote preferred orientations [001]/[100] resulting a thiner ferroelectric-platinum interface layer, which causes the improvement of fatigue and retain behaviour, despite the use of platinum electrodes. These experimental finds let to cosider the described methode of processing very convenient to prepare thin films of this composition to use on switching applications such as non volatil RAM memories.Peer reviewe

    Plant-microbe interactions and the new biotechnological methods of plant disease control

    Get PDF
    Plants constitute an excellent ecosystem for microorganisms. The environmental conditions offered differ considerably between the highly variable aerial plant part and the more stable root system. Microbes interact with plant tissues and cells with different degrees of dependence. The most interesting from the microbial ecology point of view, however, are specific interactions developed by plant-beneficial (either non-symbiotic or symbiotic) and pathogenic microorganisms. Plants, like humans and other animals, also become sick, but they have evolved a sophisticated defense response against microbes, based on a combination of constitutive and inducible responses which can be localized or spread throughout plant organs and tissues. The response is mediated by several messenger molecules that activate pathogen-responsive genes coding for enzymes or antimicrobial compounds, and produces less sophisticated and specific compounds than immunoglobulins in animals. However, the response specifically detects intracellularly a type of protein of the pathogen based on a gene-for-gene interaction recognition system, triggering a biochemical attack and programmed cell death. Several implications for the management of plant diseases are derived from knowledge of the basis of the specificity of plant-bacteria interactions. New biotechnological products are currently being developed based on stimulation of the plant defense response, and on the use of plant-beneficial bacteria for biological control of plant diseases (biopesticides) and for plant growth promotion (biofertilizers)

    Hadronic Vacuum Polarization and the Lamb Shift

    Get PDF
    Recent improvements in the determination of the running of the fine-structure constant also allow an update of the hadronic vacuum-polarization contribution to the Lamb shift. We find a shift of -3.40(7) kHz to the 1S level of hydrogen. We also comment on the contribution of this effect to the determination by elastic electron scattering of the r.m.s. radii of nuclei.Comment: 7 pages, latex, 1 figure -- Submitted to Phys. Rev. A -- epsfig.sty require

    Characterization of activated sludge settling properties with a sludge collapse-acceleration stage

    Full text link
    [EN] The sedimentability of the activated sludge can be affected by the presence of a large variety of coagulants and polymers from a previous physical-chemical process. In this paper, the activated sludge settling process in industrial wastewater treatment plants where the sludge does not settle in a conventional way is studied. The two observed constant hindered settling velocity stages and the instant the intermediate sludge acceleration period occurs are described. A variation of the Richardson and Zaki model is used to characterize the two stages of constant settling velocity. The concentration of suspended solids, where a sudden decrease of hindered settling velocity was observed, is calculated. Finally, a new hypothesis to explain the processes triggering the collapse of the initial homogeneous sludge structure and the existence of an acceleration period is formulated.Asensi Dasí, EJ.; Alemany Martínez, E.; Seco Torrecillas, A.; Ferrer, J. (2019). Characterization of activated sludge settling properties with a sludge collapse-acceleration stage. Separation and Purification Technology. 209:32-41. https://doi.org/10.1016/j.seppur.2018.07.006S324120

    Detection and nudge-intervention on sensitive information in social networks

    Full text link
    [EN] Detecting sensitive information considering privacy is a relevant issue on Online Social Networks (OSNs). It is often difficult for users to manage the privacy associated with their posts on social networks taking into account all the possible consequences. The aim of this work is to provide information about the sensitivity of the content of a publication when a user is going to share it in OSN. For this purpose, we developed a privacy-assistant agent that detects sensitive information. Based on this information, the agent provides a message through a nudge mechanism warning about the possible risks of sharing the message. To avoid being annoying, the agent also considers the user's previous behaviour (e.g. if he previously ignored certain nudges) and adapts the messages it sends to give more relevance to those categories that are more important to the user from the point of view of the privacy risk. This agent was integrated into the social network Pesedia. We analysed the performance of different models to detect a set of sensitive categories (i.e. location, medical, drug/alcohol, emotion, personal attacks, stereotyping, family and association details, personal details and personally identifiable information) in a dataset of tweets in Spanish. The model that obtained the best results (i.e. F1 and accuracy) and that was finally integrated into the privacy-assistant agent was transformer-based.This work is supported by the Spanish Government project TIN2017-89156-R.Alemany, J.; Botti-Cebriá, V.; Del Val Noguera, E.; García-Fornes, A. (2022). Detection and nudge-intervention on sensitive information in social networks. Logic Journal of IGPL. 30(6):942-953. https://doi.org/10.1093/jigpal/jzac00494295330
    corecore