100,376 research outputs found

    Partially composite Goldstone Higgs boson

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    We consider a model of dynamical electroweak symmetry breaking with a partially composite Goldstone Higgs boson. The model is based on a strongly interacting fermionic sector coupled to a fundamental scalar sector via Yukawa interactions. The SU(4) x SU(4) global symmetry of these two sectors is broken to a single SU(4) via Yukawa interactions. Electroweak symmetry breaking is dynamically induced by condensation due to the strong interactions in the new fermionic sector which further breaks the global symmetry SU(4) -> Sp(4). The Higgs boson arises as a partially composite state which is an exact Goldstone boson in the limit where SM interactions are turned off. Terms breaking the SU(4) global symmetry explicitly generate a mass for the Goldstone Higgs boson. The model realizes in different limits both (partially) composite Higgs and (bosonic) technicolor models, thereby providing a convenient unified framework for phenomenological studies of composite dynamics. It is also a dynamical extension of the recent elementary Goldstone Higgs model

    Radiatively induced Fermi scale and unification

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    We consider extensions of the Standard Model in which the hierarchy between the unification and the Fermi scale emerges radiatively. Within the Pati-Salam framework, we show that it is possible to construct a viable model where the Higgs is an elementary pseudo-Goldstone boson, and the correct hierarchy is generated

    1. Erkki VALLI, Zur Verfasserfrage der Konigsberger Apostelgeschichte, Helsinki, 1947. (Suomalaisen Tiedeakatemian Toimituksia. Annales Academiae scientiarum Fennicae, Ser. B, t. 61). — 2. Eero ALANNE, Die deutsche Weinbauterminologie in althochdeutscher une mittelhochdeutscher Zeit, ibid., 1950. (Ibid., t. 65). — 3. E. O. KUUJO, Das Zehntwesen in der Erzdiozese Hamburg-Вremen bis zu seiner Privatisierung, ibid., 1949. (Ibid., t. 62).

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    B. E. 1. Erkki VALLI, Zur Verfasserfrage der Konigsberger Apostelgeschichte, Helsinki, 1947. (Suomalaisen Tiedeakatemian Toimituksia. Annales Academiae scientiarum Fennicae, Ser. B, t. 61). — 2. Eero ALANNE, Die deutsche Weinbauterminologie in althochdeutscher une mittelhochdeutscher Zeit, ibid., 1950. (Ibid., t. 65). — 3. E. O. KUUJO, Das Zehntwesen in der Erzdiozese Hamburg-Вremen bis zu seiner Privatisierung, ibid., 1949. (Ibid., t. 62). In: Bibliothèque de l'école des chartes. 1952, tome 110. pp. 298-301

    Model-independent constraints with extended dark matter EFT

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    We systematically explore the phenomenology of the recently proposed extended dark matter effective field theory (eDMeft), which allows for a consistent effective description of DM scenarios across different energy scales. The framework remains applicable at collider energies and is capable of reproducing the correct relic abundance by including a dynamical mediator particle to the dark sector, while maintaining correlations dictated by gauge invariance in a ‘model-independent’ way. Taking into account present and future constraints from direct- and indirect-detection experiments, from collider searches for missing energy and for scalar resonances in vector-boson, di-jet, and Higgs-pair final states, as well as from the relic abundance as measured by Planck, we determine viable regions in the parameter space, both for scalar and pseudoscalar mediator. In particular, we point out regions where cancellations in the direct-detection cross section appear leading to allowed islands for scalar mediators that could be missed in a naive simplified-model approach, but are present in the full D = 5 effective theory, as well as a general opening of the parameter space due to consistently considering all operators at a given mass dimension. Thus, canonical WIMP-like scenarios can survive even the next generation of direct-detection experiments in different mass regimes, while potentially becoming testable at the high-luminosity LHC

    Dark matter in (partially) composite Higgs models

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    Abstract We construct composite and partially composite Higgs models with complex pseudo-Nambu-Goldstone (pNGB) dark matter states from four-dimensional gauge-Yukawa theories with strongly interacting fermions. The fermions are partially gauged under the electroweak symmetry, and the dynamical electroweak symmetry breaking sector is minimal. The pNGB dark matter particle is stable due to a U(1) technibaryon-like symmetry, also present in the technicolor limit of the models. However, the relic density is particle anti-particle symmetric and due to thermal freeze-out as opposed to the technicolor limit where it is typically due to an asymmetry. The pNGB Higgs is composite or partially composite depending on the origin of the Standard Model fermion masses, which impacts the dark matter phenomenology. We illustrate the important features with a model example invariant under an SU(4) × SU(2) × U(1) global symmetry

    Letter, [Author unclear] to Paulina T. Merritt

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    Handwritten letter to Paulina Merritt from an unknown author, October 1, 1876.

    Testing a dynamical origin of standard model fermion masses

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    We discuss a test of the Standard Model fermion mass origin in models of dynamical electroweak symmetry breaking. The couplings of composite pseudoscalar resonances to top quarks allow us to distinguish high-scale extended-technicolor-type fermion mass generation from fermion partial compositeness and low-scale mass generation via an induced vacuum expectation value of a doublet coupled to the composite sector. These different possible origins of fermion masses are thus accessible via weak-scale physics searched for at the LHC

    Handwritten biographical information on Paulina T. McClung Merritt

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    A handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.

    Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.

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    IFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods
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