11,795 research outputs found

    Flavor Gauge Models Below the Fermi Scale

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    The mass and weak interaction eigenstates for the quarks of the third generation are very well aligned, an empirical fact for which the Standard Model offers no explanation. We explore the possibility that this alignment is due to an additional gauge symmetry in the third generation. Specifically, we construct and analyze an explicit, renormalizable model with a gauge boson, XX, corresponding to the B−LB-L symmetry of the third family. Having a relatively light (in the MeV to multi-GeV range), flavor-nonuniversal gauge boson results in a variety of constraints from different sources. By systematically analyzing 20 different constraints, we identify the most sensitive probes: kaon, B+B^+, D+D^+ and Upsilon decays, D−Dˉ0D-\bar{D}^0 mixing, atomic parity violation, and neutrino scattering and oscillations. For the new gauge coupling gXg_X in the range (10−2−10−4)(10^{-2} - 10^{-4}) the model is shown to be consistent with the data. Possible ways of testing the model in bb physics, top and ZZ decays, direct collider production and neutrino oscillation experiments, where one can observe nonstandard matter effects, are outlined. The choice of leptons to carry the new force is ambiguous, resulting in additional phenomenological implications, such as non-universality in semileptonic bottom decays. The proposed framework provides interesting connections between neutrino oscillations, flavor and collider physics.Comment: 44 pages, 7 figures, 3 tables; B physics constraints and references added, conclusions unchange

    On the renormalization of the electroweak chiral Lagrangian with a Higgs

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    We consider the scalar sector of the effective non-linear electroweak Lagrangian with a light "Higgs" particle, up to four derivatives in the chiral expansion. The complete off-shell renormalization procedure is implemented, including one loop corrections stemming from the leading two-derivative terms, for finite Higgs mass. This determines the complete set of independent chiral invariant scalar counterterms required for consistency; these include bosonic operators often disregarded. Furthermore, new counterterms involving the Higgs particle which are apparently chiral non-invariant are identified in the perturbative analysis. A novel general parametrization of the pseudoescalar field redefinitions is proposed, which reduces to the various usual ones for specific values of its parameter; the non-local field redefinitions reabsorbing all chiral non-invariant counterterms are then explicitly determined. The physical results translate into renormalization group equations which may be useful when comparing future Higgs data at different energies

    Blue rubber-bleb nevus syndrome: report of a familial case with a dural arteriovenous fistula

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    We report a case of a 45-year-old woman known to have a familial form of blue rubber-bleb nevus syndrome (BRBNS). The patient developed severe occipital headaches and bilateral retroauricular bruits. Cerebral angiography showed a large dural arteriovenous fistula in the torcular region. Central nervous system involvement in BRBNS is not often reported, and most cases of BRBNS are sporadic

    Anålises patentométrica, bibliométrica e do portfólio de projetos da Embrapa relacionados a Elaeis sp.

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    bitstream/item/79835/1/CITE-12.pd

    Infrared behavior of interacting bosons at zero temperature

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    We review the infrared behavior of interacting bosons at zero temperature. After a brief discussion of the Bogoliubov approximation and the breakdown of perturbation theory due to infrared divergences, we present two approaches that are free of infrared divergences -- Popov's hydrodynamic theory and the non-perturbative renormalization group -- and allow us to obtain the exact infrared behavior of the correlation functions. We also point out the connection between the infrared behavior in the superfluid phase and the critical behavior at the superfluid--Mott-insulator transition in the Bose-Hubbard model.Comment: 8 pages, 4 figures. Proceedings of the 19th International Laser Physics Workshop, LPHYS'10 (Foz do Iguacu, Brazil, July 5-9, 2010

    J. Silvaa , N. Hipolito b,c , P. Machadob , S. Florab , J. Cruza,b, *

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    Acknowledgements: This work is part of a project funded by FEDER - Fundo Europeu de Desenvolvimento Regional by COMPETE 2020 Programa Operacional Competitividade e Internacionalização (POCI) and national funds by Fundação ao para a CiĂȘncia e a Tecnologia (FCT), entitled ^ “OnTRACK project - Time to Rethink Activity Knowledge: a personalized mHealth coaching platform to tackle physical inactivity in COPD” (POCI-01-0145-FEDER-028446, PTDC/SAU-SER/28446/2017). SF and NH are being financially supported by PhD fellowships DFA/BD/6954/2020 and 2021.05188.BD, respectively, funded by FCT/MCTES, FSE, Por_Centro and UE. PM acknowledges the support provided by the FCT with the PhD fellowship. The authors acknowledge the financial support provided by FCT to their research unit Center for Innovative Care and Health Technology (UIDB/05704/2020).Pulmonology is the official journal of the Portuguese Society of Pulmonology (Sociedade Portuguesa de Pneumologia/SPP). The journal publishes 6 issues per year, mainly about respiratory system diseases in adults and clinical research. All articles published open access will be immediately and permanently free for everyone to read, download, copy and distribute.Introduction: Low physical activity (PA) levels have a negative impact on the health status of patients with Chronic Obstructive Pulmonary Disease (COPD). Smartphone applications (apps) focused on PA promotion may mitigate this problem; however, their effectiveness depends on patient adherence, which can be influenced by the technological features of the apps. This systematic review identified the technological features of smartphone apps aiming to promote PA in patients with COPD. Methods: A literature search was performed in the databases ACM Digital Library, IEEE Xplore, PubMed, Scopus and Web of Science. Papers including the description of a smartphone app for PA promotion in patients with COPD were included. Two researchers independently selected studies and scored the apps features based on a previously developed framework (38 possible features). Results: Twenty-three studies were included and 19 apps identified, with an average of 10 technological features implemented. Eight apps could be connected to wearables to collect data. The categories ‘Measuring and monitoring’ and ‘Support and Feedback’ were present in all apps. Overall, the most implemented features were ‘progress in visual format’ (n=13), ‘advice on PA’ (n=14) and ‘data in visual format’ (n=10). Only three apps included social features, and two included a web-based version of the app. Conclusions: The existing smartphone apps include a relatively small number of features to promote PA, which are mostly related to monitoring and providing feedback. Further research is warranted to explore the relationship between the presence/absence of specific features and the impact of interventions on patients’ PA levels.info:eu-repo/semantics/publishedVersio
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