10,821 research outputs found

    Quadratic Contributions of Softly Broken Supersymmetry in the Light of Loop Regularization

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    Loop regularization (LORE) is a novel regularization scheme in modern quantum field theories. It makes no change to the spacetime structure and respects both gauge symmetries and supersymmetry. As a result, LORE should be useful in calculating loop corrections in supersymmetry phenomenology. To demonstrate further its power, in this article we revisit in the light of LORE the old issue of the absence of quadratic contributions (quadratic divergences) in softly broken supersymmetric field theories. It is shown explicitly by Feynman diagrammatic calculations that up to two loops the Wess-Zumino model with soft supersymmetry breaking terms (WZ' model), one of the simplest models with the explicit supersymmetry breaking, is free of quadratic contributions. All the quadratic contributions cancel with each other perfectly, which is consistent with results dictated by the supergraph techniques.Comment: 25 pages, 3 figures; accepted versio

    Neural Reranking for Named Entity Recognition

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    We propose a neural reranking system for named entity recognition (NER). The basic idea is to leverage recurrent neural network models to learn sentence-level patterns that involve named entity mentions. In particular, given an output sentence produced by a baseline NER model, we replace all entity mentions, such as \textit{Barack Obama}, into their entity types, such as \textit{PER}. The resulting sentence patterns contain direct output information, yet is less sparse without specific named entities. For example, "PER was born in LOC" can be such a pattern. LSTM and CNN structures are utilised for learning deep representations of such sentences for reranking. Results show that our system can significantly improve the NER accuracies over two different baselines, giving the best reported results on a standard benchmark.Comment: Accepted as regular paper by RANLP 201

    Explicitly Broken Supersymmetry with Exactly Massless Moduli

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    There is an avatar of the little hierarchy problem of the MSSM in 3-dimensional supersymmetry. We propose a solution to this problem in AdS3_3 based on the AdS/CFT correspondence. The bulk theory is a supergravity theory in which U(1) ×\times U(1) R-symmetry is gauged by Chern-Simons fields. The bulk theory is deformed by a boundary term quadratic in the gauge fields. It breaks SUSY completely and sources an exactly marginal operator in the dual CFT. SUSY breaking is communicated by gauge interactions to bulk scalar fields and their spinor superpartners. Since the R-charges of scalar and spinor differ, this generates a SUSY breaking shift of their masses. The Ward identity facilitates the calculation of these mass shifts to any desired order in the strength of the deformation. Moduli fields are massless RR-neutral bulk scalars with vanishing potential in the undeformed theory. These properties are maintained to all orders in the deformation despite the fact that moduli couple in the bulk to loops of R-charged fields.Comment: Match to published version. All order corrections, i.e. exact results after SUSY breaking, are show

    Quantum Electroweak Symmetry Breaking Through Loop Quadratic Contributions

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    Based on two postulations that (i) the Higgs boson has a large bare mass mH≫mh≃125m_H \gg m_h \simeq 125 GeV at the characteristic energy scale McM_c which defines the standard model (SM) in the ultraviolet region, and (ii) quadratic contributions of Feynman loop diagrams in quantum field theories are physically meaningful, we show that the SM electroweak symmetry breaking is induced by the quadratic contributions from loop effects. As the quadratic running of Higgs mass parameter leads to an additive renormalization, which distinguishes from the logarithmic running with a multiplicative renormalization, the symmetry breaking occurs once the sliding energy scale μ\mu moves from McM_c down to a transition scale μ=ΛEW\mu =\Lambda_{EW} at which the additive renormalized Higgs mass parameter mH2(Mc/μ)m^2_H(M_c/\mu) gets to change the sign. With the input of current experimental data, this symmetry breaking energy scale is found to be ΛEW≃760\Lambda_{EW}\simeq 760 GeV, which provides another basic energy scale for the SM besides McM_c. Studying such a symmetry breaking mechanism could play an important role in understanding both the hierarchy problem and naturalness problem. It also provides a possible way to explore the experimental implications of the quadratic contributions as ΛEW\Lambda_{EW} lies within the probing reach of the LHC and the future Great Collider.Comment: 10 pages, 2 figures, published versio
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