5,465 research outputs found

    Heavy Quark Symmetry Violation in Semileptonic Decays of D Mesons

    Full text link
    The decays of DD mesons to KlνK l \nu and KlνK^* l \nu final states exhibit significant deviations from the predictions of heavy-quark symmetry, as one might expect since the strange quark's mass is of the same order as the QCD scale. Nonetheless, in order to understand where the most significant effects might lie for heavier systems (such as BDlνB \to D l\nu and BDlνB \to D^* l\nu), the pattern of these deviations is analyzed from the standpoint of perturbative QCD and O(1/ms){\cal O}(1/m_s) corrections. Two main effects are noted. First, the perturbative QCD corrections lead to an overall decrease of predicted rates, which can be understood in terms of production of excited kaonic states. Second, O(1/ms){\cal O}(1/m_s) effects tend to cancel the perturbative QCD corrections in the case of KlνKl\nu decay, while they have minimal effect in KlνK^*l\nu decay.Comment: 25 pages (LaTeX) + 7 pages of Postscript figures (included at end), EFI-92-3

    Efeito da adubação orgânica no desenvolvimento e rendimento do inhame da costa (Dioscorea cayennensis) em sistema irrigado no Submédio do Vale do São Francisco.

    Get PDF
    A cultura do inhame na região Nordeste é considerada como uma cultura tradicional entre os pequenos agricultores. No entanto, estudos recentes comprovam uma diminuição na produção, devido a diversos fatores, entre esses a baixa fertilidade dos solos. Objetivando avaliar o efeito do uso de adubo orgânico no rendimento do inhame da Costa (Dioscorea cayennensis) cultivado sobre sistema de irrigação foram aplicados doses de 0,0; 2,0 e 3,0 litros (L) de esterco de caprinos na cova. O ensaio foi conduzido em área irrigada na Estação Experimental de Bebedouro da Embrapa Semiárido, município de Petrolina-PE, de março a agosto de 2012. O ensaio foi conduzido no período de estiagem utilizando uma lâmina média de 12 mm por irrigação duas vezes por semana. O plantio foi realizado em março de 2012 e a colheita foi realizada aos sete meses após o plantio. As análises químicas do solo foram realizadas antes do plantio em três profundidades. Conforme resultados, a maior produtividade foi alcançada na dose de 2 litros de esterco por cova, com produção de túberas de 27.5 t/ha, superando significativamente a testemunha (ausência de esterco), com ganho de 10,2 t/ha. De modo geral o uso de adubo orgânico pode contribuir significativamente para aumentar a produção de inhame e melhorar a qualidade das túberas

    Sibilant consonants classification with deep neural networks

    Get PDF
    Abstract. Many children su ering from speech sound disorders cannot pronounce the sibilant consonants correctly. We have developed a serious game that is controlled by the children's voices in real time and that allows children to practice the European Portuguese sibilant consonants. For this, the game uses a sibilant consonant classi er. Since the game does not require any type of adult supervision, children can practice the production of these sounds more often, which may lead to faster improvements of their speech. Recently, the use of deep neural networks has given considerable improvements in classi cation for a variety of use cases, from image classication to speech and language processing. Here we propose to use deep convolutional neural networks to classify sibilant phonemes of European Portuguese in our serious game for speech and language therapy. We compared the performance of several diferent arti cial neural networks that used Mel frequency cepstral coefcients or log Mel lterbanks. Our best deep learning model achieves classi cation scores of 95:48% using a 2D convolutional model with log Mel lterbanks as input features.info:eu-repo/semantics/publishedVersio

    Resonant and nonresonant D+ -> K- pi+ l+ nu(l) semileptonic decays

    Full text link
    We analyse the semileptonic decay D+ -> K- pi+ l+ nu(l) using an effective Lagrangian developed previously to describe the decays D -> P l nu(l) and D -> V l nu(l). Light vector mesons are included in the model which combines the heavy quark effective Lagrangian and chiral perturbation theory approach. The nonresonant and resonant contributions are compared. With no new parameters the model correctly reproduces the measured ratio Gamma(nres)/Gamma(nres + res). We also present useful nonresonant decay distributions. Finally, a similar model, but with a modified current which satisfies the soft pion theorems at the expense of introducing another parameter, is analyzed and the results of the models are compared.Comment: 17 pages, 3 Postscript figures, standard Latex, extended revision, title, abstract and text (especially Sec. IV) changed, results unchange

    Hot water treatment as and alternative control of postharvest decay of mango.

    Get PDF
    This study was undertaken to determine the effects of hot water treatment to contraI postharvest decay of mango
    corecore