16,608 research outputs found

    Lepton number violation phenomenology of d=7 neutrino mass models

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    We study the phenomenology of d=7 1-loop neutrino mass models. All models in this particular class require the existence of several new SU(2)LSU(2)_L multiplets, both scalar and fermionic, and thus predict a rich phenomenology at the LHC. The observed neutrino masses and mixings can easily be fitted in these models. Interestingly, despite the smallness of the observed neutrino masses, some particular lepton number violating (LNV) final states can arise with observable branching ratios. These LNV final states consists of leptons and gauge bosons with high multiplicities, such as 4l+4W, 6l+2W, etc. We study current constraints on these models from upper bounds on charged lepton flavour violating decays, existing lepton number conserving searches at the LHC and discuss possible future LNV searches

    Quantum Monte Carlo and exact diagonalization study of a dynamic Hubbard model

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    A one-dimensional model of electrons locally coupled to spin-1/2 degrees of freedom is studied by numerical techniques. The model is one in the class of dynamicdynamic HubbardHubbard modelsmodels that describe the relaxation of an atomic orbital upon double electron occupancy due to electron-electron interactions. We study the parameter regime where pairing occurs in this model by exact diagonalization of small clusters. World line quantum Monte Carlo simulations support the results of exact diagonalization for larger systems and show that kinetic energy is lowered when pairing occurs. The qualitative physics of this model and others in its class, obtained through approximate analytic calculations, is that superconductivity occurs through hole undressing even in parameter regimes where the effective on-site interaction is strongly repulsive. Our numerical results confirm the expected qualitative behavior, and show that pairing will occur in a substantially larger parameter regime than predicted by the approximate low energy effective Hamiltonian.Comment: Some changes made in response to referees comments. To be published in Phys.Rev.

    PLOTTER: An independent computer program for the generation of graphical displays

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    A computer program is described for generating graphical information from input data or auxiliary analysis programs on a variety of graphical devices. Options are presented for tabulating the data in columnar format and for plotting auxiliary text in the vicinity of the plotted information. Display device selection is accomplished by interfacing the basic computer code through routines which convert the internally generated plot vectors to hardware commands for the display device. The plotting techniques employed in the computer program are discussed. User's instructions are presented with examples which illustrate the use of the program in generating plotted information from various sources and presenting the information in alternate plot formats. Technical discussion of the computer code is presented giving the physical characteristics, computer loading instructions and descriptions of the subroutines

    Development of the engineering design integration (EDIN) system: A computer aided design development

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    The EDIN (Engineering Design Integration) System which provides a collection of hardware and software, enabling the engineer to perform man-in-the-loop interactive evaluation of aerospace vehicle concepts, was considered. Study efforts were concentrated in the following areas: (1) integration of hardware with the Univac Exec 8 System; (2) development of interactive software for the EDIN System; (3) upgrading of the EDIN technology module library to an interactive status; (4) verification of the soundness of the developing EDIN System; (5) support of NASA in design analysis studies using the EDIN System; (6) provide training and documentation in the use of the EDIN System; and (7) provide an implementation plan for the next phase of development and recommendations for meeting long range objectives

    Founding brothers: Leland, buck, and cappon and the formation of the archives profession (session 404)

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    This session on archives history examines the role of three individuals-Waldo G. Leland (1879-1966), Solon J. Buck (1884-1962), and Lester J. Cappon (1900-1981)-in the formation of the archives profession in the United States in the first three-quarters of the twentieth century. These "founding brothers" published extensively, but they also created and maintained personal manuscript collections that reflect how they viewed themselves and how they wanted to be remembered. Four archivists/historians track through the lenses of the papers of the "founding brothers" the emergence of professional history to the beginnings of public history with their alliance and tension with archival science as a distinct profession

    Superconductivity from Undressing. II. Single Particle Green's Function and Photoemission in Cuprates

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    Experimental evidence indicates that the superconducting transition in high TcT_c cuprates is an 'undressing' transition. Microscopic mechanisms giving rise to this physics were discussed in the first paper of this series. Here we discuss the calculation of the single particle Green's function and spectral function for Hamiltonians describing undressing transitions in the normal and superconducting states. A single parameter, Υ\Upsilon, describes the strength of the undressing process and drives the transition to superconductivity. In the normal state, the spectral function evolves from predominantly incoherent to partly coherent as the hole concentration increases. In the superconducting state, the 'normal' Green's function acquires a contribution from the anomalous Green's function when Υ \Upsilon is non-zero; the resulting contribution to the spectral function is positivepositive for hole extraction and negativenegative for hole injection. It is proposed that these results explain the observation of sharp quasiparticle states in the superconducting state of cuprates along the (π,0)(\pi,0) direction and their absence along the (π,π)(\pi,\pi) direction.Comment: figures have been condensed in fewer pages for easier readin

    Evolving text classification rules with genetic programming

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    We describe a novel method for using genetic programming to create compact classification rules using combinations of N-grams (character strings). Genetic programs acquire fitness by producing rules that are effective classifiers in terms of precision and recall when evaluated against a set of training documents. We describe a set of functions and terminals and provide results from a classification task using the Reuters 21578 dataset. We also suggest that the rules may have a number of other uses beyond classification and provide a basis for text mining applications

    Clinical potential of necitumumab in non-small cell lung carcinoma

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    Despite significant progress, new therapeutic approaches for advanced non-small cell lung cancer (NSCLC) are highly needed, particularly for the treatment of patients with squamous cell carcinoma. The epidermal growth factor receptor (EGFR) is often overexpressed in NSCLC and represents a relevant target for specific treatments. Although EGFR mutations are more frequent in non-squamous histology, the receptor itself is more often overexpressed in squamous NSCLC. Necitumumab is a human monoclonal antibody that is able to inhibit the EGFR pathway and cause antibody-dependent cell cytotoxicity. This drug has been studied in combination with first-line chemotherapy for advanced NSCLC in two Phase III trials, and a significant survival benefit was reported in squamous NSCLC (SQUIRE trial); by contrast, necitumumab did not prove itself beneficial in non-squamous histotype (INSPIRE trial). On the basis of the SQUIRE results, necitumumab was approved in combination with cisplatin and gemcitabine as a first-line treatment for advanced squamous NSCLC, both in the US and Europe, where its availability is limited to patients with EGFRexpressing tumors. The aim of this review is to describe the tolerability and the efficacy of necitumumab by searching the available published data and define its potential role in the current landscape of NSCLC treatment

    R-parity Conserving Supersymmetry, Neutrino Mass and Neutrinoless Double Beta Decay

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    We consider contributions of R-parity conserving softly broken supersymmetry (SUSY) to neutrinoless double beta (\znbb) decay via the (B-L)-violating sneutrino mass term. The latter is a generic ingredient of any weak-scale SUSY model with a Majorana neutrino mass. The new R-parity conserving SUSY contributions to \znbb are realized at the level of box diagrams. We derive the effective Lagrangian describing the SUSY-box mechanism of \znbb-decay and the corresponding nuclear matrix elements. The 1-loop sneutrino contribution to the Majorana neutrino mass is also derived. Given the data on the \znbb-decay half-life of 76^{76}Ge and the neutrino mass we obtain constraints on the (B-L)-violating sneutrino mass. These constraints leave room for accelerator searches for certain manifestations of the 2nd and 3rd generation (B-L)-violating sneutrino mass term, but are most probably too tight for first generation (B-L)-violating sneutrino masses to be searched for directly.Comment: LATEX, 29 pages + 4 (uuencoded) figures appende
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