5 research outputs found

    Extended Goldstone-Boson-Exchange Constituent Quark Model

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    We present an extension of the Goldstone-boson-exchange constituent quark model including additional interactions beyond the ones used hitherto. For the hyperfine interaction between the constituent quarks we assume pseudoscalar, vector, and scalar meson exchanges and consider all relevant force components produced by these types of exchanges. The resulting model, which corresponds to a relativistic Poincare-invariant Hamiltonian (or equivalently mass operator), provides a unified framework for a covariant description of all light and strange baryons. The ground states and resonances up to an excitation energy of about 2 GeV are reproduced in fair agreement with phenomenology, with the exception of the first excitations above the Lambda and Xi ground states.Comment: 11 pages, 4 figures, 3 tables; substantial revisions, additional author, bibliography extended and update

    How do 5-year-olds understand questions? Differences in languages across Europe

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    The comprehension of constituent questions is an important topic for language acquisition research and for applications in the diagnosis of language impairment. This article presents the results of a study investigating the comprehension of different types of questions by 5-year-old, typically developing children across 19 European countries, 18 different languages, and 7 language (sub-)families. The study investigated the effects of two factors on question formation: (a) whether the question contains a simple interrogative word like 'who' or a complex one like 'which princess', and (b) whether the question word was related to the sentential subject or object position of the verb. The findings show that there is considerable variation among languages, but the two factors mentioned consistently affect children's performance. The cross-linguistic variation shows that three linguistic factors facilitate children's understanding of questions: having overt case morphology, having a single lexical item for both 'who' and 'which', and the use of synthetic verbal forms
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