16,852 research outputs found

    Effects of the R-parity violation in the minimal supersymmetric standard model on dilepton pair production at the CERN LHC

    Get PDF
    We investigate in detail the effects of the R-parity lepton number violation in the minimal supersymmetric standard model (MSSM) on the parent process pp→e+e−+Xpp \to e^+ e^- + X at the CERN Large Hadron Collider (LHC). The numerical comparisons between the contributions of the R-parity violating effects to the parent process via the Drell-Yan subprocess and the gluon-gluon fusion are made. We find that the R-violating effects on e+e−e^+ e^- pair production at the LHC could be significant. The results show that the cross section of the e+e− e^+ e^- pair productions via gluon-gluon collision at the LHC can be of the order of 10210^2 fb, and this subprocess maybe competitive with the production mechanism via the Drell-Yan subprocess. We give also quantitatively the analysis of the effects from both the mass of sneutrino and coupling strength of the R-parity violating interactions.Comment: 18 pages, 10 figures, accepted by Phys. Rev.

    Searches for Gravitational Waves from Binary Neutron Stars: A Review

    Full text link
    A new generation of observatories is looking for gravitational waves. These waves, emitted by highly relativistic systems, will open a new window for ob- servation of the cosmos when they are detected. Among the most promising sources of gravitational waves for these observatories are compact binaries in the final min- utes before coalescence. In this article, we review in brief interferometric searches for gravitational waves emitted by neutron star binaries, including the theory, instru- mentation and methods. No detections have been made to date. However, the best direct observational limits on coalescence rates have been set, and instrumentation and analysis methods continue to be refined toward the ultimate goal of defining the new field of gravitational wave astronomy.Comment: 30 pages, 5 Figures, to appear in "Short-Period Binary Stars: Observations, Analyses, and Results", Ed.s Eugene F. Milone, Denis A. Leahy, David W. Hobil

    Interferometer Response to Scalar Gravitational Waves

    Full text link
    It was recently suggested that the magnetic component of Gravitational Waves (GWs) is relevant in the evaluation of frequency response functions of gravitational interferometers. In this paper we extend the analysis to the magnetic component of the scalar mode of GWs which arise from scalar-tensor gravity theory. In the low-frequency approximation, the response function of ground-based interferometers is calculated. The angular dependence of the electric and magnetic contributions to the response function is discussed. Finally, for an arbitrary frequency range, the proper distance between two test masses is calculated and its usefulness in the high-frequency limit for space-based interferometers is briefly considered.Comment: Accepted for publication by Int. Journ. Mod. Phys. D. Final versio

    The Prediction of Mass of Z'-Boson from bq0−bq0barb_q^0-b_q^0 bar Mixing

    Full text link
    B_q^0-B_^0 bar mixing offers a profound probe into the effects of new physics beyond the Standard Model. In this paper, Bs0−Bs0barB_s^0-B_s^0 bar and Bd0−Bd0barB_d^0-B_d^0 bar mass differences are considered taking the effect of both Z-and Z' -mediated flavour-changing neutral currents in the Bq0−Bq0barB_q^0-B_q^0 bar mixing (q = d, s). Our estimated mass of Z' boson is accessible at the experiments LHC and B-factories in near future.Comment: 11 pages, 02 Figure

    Spectral Line Removal in the LIGO Data Analysis System (LDAS)

    Full text link
    High power in narrow frequency bands, spectral lines, are a feature of an interferometric gravitational wave detector's output. Some lines are coherent between interferometers, in particular, the 2 km and 4 km LIGO Hanford instruments. This is of concern to data analysis techniques, such as the stochastic background search, that use correlations between instruments to detect gravitational radiation. Several techniques of `line removal' have been proposed. Where a line is attributable to a measurable environmental disturbance, a simple linear model may be fitted to predict, and subsequently subtract away, that line. This technique has been implemented (as the command oelslr) in the LIGO Data Analysis System (LDAS). We demonstrate its application to LIGO S1 data.Comment: 11 pages, 5 figures, to be published in CQG GWDAW02 proceeding

    The nutritional care of people living with dementia at home: A scoping review.

    Get PDF
    There are an increasing number of people with dementia living in their own home for longer, often supported by a family member. The symptoms of dementia can affect an individual's nutritional status, which can lead to a reduced quality of life for the person with dementia and their family members. A scoping review was conducted from July 2016 until September 2016, using a recognised framework, to explore what is currently known, and identify any gaps in the research regarding the nutritional care of people living with dementia at home. This included any interventions that may have been trialled or implemented, and the views of those living with dementia, carers and clinicians. Six electronic databases were searched from inception to July 2016. A review team was involved in screening and data extraction for selected articles. Published qualitative and quantitative studies were included that explored the nutritional care of people living with dementia at home. Methods included data extraction and conventional content analysis. Stakeholders were involved in the development of final categories. Following screening, 61 studies reported in 63 articles were included. Most studies were cross-sectional (n = 24), cohort (n = 15) or qualitative (n = 9). Only three were randomised controlled trials. Three overarching categories represented the results: Timely identification of nutritional risk and subsequent regular monitoring of nutritional status, multi-component tailored interventions and the influence of the care-giving dyad on nutritional status. Many studies identify people living at home with dementia as a vulnerable group prone to malnutrition; however, a lack of interventions exists to address the increased risk. There is a lack of research exploring the role of home care providers and healthcare professionals in the provision of nutritional care. Further research is required to explore how the emotional aspect of the care-giving dyad influences nutritional care

    Renormalizing Heavy Quark Effective Theory at O(1/m_Q^3)

    Full text link
    We present a calculation of the renormalized HQET Lagrangian at order O(1/m_Q^3) in the one particle sector. The anomalous dimensions of local operators and time ordered products of dimension 7 contributing at this order are calculated in the one loop approximation. We show that a careful treatment of the time ordered products is necessary to arrive at a gauge independent renormalized lagrangian. Our result sets the stage for an investigation of reparametrization invariance at O(1/m_Q^3).Comment: Latex, epsfig. Improved teXnology and modified conclusions. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints

    Correlation entropy of synaptic input-output dynamics

    Full text link
    The responses of synapses in the neocortex show highly stochastic and nonlinear behavior. The microscopic dynamics underlying this behavior, and its computational consequences during natural patterns of synaptic input, are not explained by conventional macroscopic models of deterministic ensemble mean dynamics. Here, we introduce the correlation entropy of the synaptic input-output map as a measure of synaptic reliability which explicitly includes the microscopic dynamics. Applying this to experimental data, we find that cortical synapses show a low-dimensional chaos driven by the natural input pattern.Comment: 7 pages, 6 Figures (7 figure files

    Structure, Deformations and Gravitational Wave Emission of Magnetars

    Full text link
    Neutron stars can have, in some phases of their life, extremely strong magnetic fields, up to 10^15-10^16 G. These objects, named magnetars, could be powerful sources of gravitational waves, since their magnetic field could determine large deformations. We discuss the structure of the magnetic field of magnetars, and the deformation induced by this field. Finally, we discuss the perspective of detection of the gravitational waves emitted by these stars.Comment: 11 pages, 2 figures, prepared for 19th International Conference on General Relativity and Gravitation (GR19), Mexico City, Mexico, July 5-9, 201

    The ACIGA Data Analysis programme

    Full text link
    The Data Analysis programme of the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA) was set up in 1998 by the first author to complement the then existing ACIGA programmes working on suspension systems, lasers and optics, and detector configurations. The ACIGA Data Analysis programme continues to contribute significantly in the field; we present an overview of our activities.Comment: 10 pages, 0 figures, accepted, Classical and Quantum Gravity, (Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 2003
    • 

    corecore