5,361 research outputs found

    Prospects for Stochastic Background Searches Using Virgo and LSC Interferometers

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    We consider the question of cross-correlation measurements using Virgo and the LSC Interferometers (LIGO Livingston, LIGO Hanford, and GEO600) to search for a stochastic gravitational-wave background. We find that inclusion of Virgo into the network will substantially improve the sensitivity to correlations above 200 Hz if all detectors are operating at their design sensitivity. This is illustrated using a simulated isotropic stochastic background signal, generated with an astrophysically-motivated spectrum, injected into 24 hours of simulated noise for the LIGO and Virgo interferometers.Comment: 11 pages, uses IOP style files, submitted to CQG for GWDAW11 proceedings; revised in response to referee comment

    Stochastic background from extra-galactic double neutron stars

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    We present Monte Carlo simulations of the extra galactic population of inspiralling double neutron stars, and estimate its contribution to the astrophysical gravitational wave background, in the frequency range of ground based interferometers, corresponding to the last thousand seconds before the last stable orbit when more than 96 percent of the signal is released. We show that sources at redshift z>0.5 contribute to a truly continuous background which may be detected by correlating third generation interferometers.Comment: 13 pages, 7 figures - proceeding of a talk given at the 11th GWDAW, to appear in CQ

    LIGO End-to-End simulation Program

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    A time-domain simulation program has been developed to provide an accurate description of interferometric gravitational wave detectors. This is being utilized to build a model of LIGO with the aim of aiding in the shakedown and integration of the interferometer subsystems, and ultimately the optimization of detector sensitivity

    On line power spectra identification and whitening for the noise in interferometric gravitational wave detectors

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    In this paper we address both to the problem of identifying the noise Power Spectral Density of interferometric detectors by parametric techniques and to the problem of the whitening procedure of the sequence of data. We will concentrate the study on a Power Spectral Density like the one of the Italian-French detector VIRGO and we show that with a reasonable finite number of parameters we succeed in modeling a spectrum like the theoretical one of VIRGO, reproducing all its features. We propose also the use of adaptive techniques to identify and to whiten on line the data of interferometric detectors. We analyze the behavior of the adaptive techniques in the field of stochastic gradient and in the Least Squares ones.Comment: 28 pages, 21 figures, uses iopart.cls accepted for pubblication on Classical and Quantum Gravit

    The CP asymmetry for B--> K^* l^+ l^- decay in the general two Higgs doublet model

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    We study CP asymmetry for the exclusive decay B --> K^* l^+ l^- in the two Higgs doublet model with three level flavor changing neutral currents (model III). We analyse the dependency of this quantity to the new phase coming from the complex Yukawa couplings in the theory and we find that there exist a considerable CP violation for the relevant process. Further, we see that the sign of the Wilson coefficient C_7^{eff} can be determined by fixing dilepton mass. Therefore, the future measurements of CP asymmetry for B --> K^* l^+ l^- decay will give a powerful information about the sign of Wilson coefficient C_{7}^{eff} and the new physics beyond the SM.Comment: 22 pages, 8 figure

    Can bsγb\to s\gamma Close the Supersymmetric Higgs Production Window?

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    We show that the present limit from CLEO on the inclusive decay bsγb\to s\gamma provides strong constraints on the parameters of the charged Higgs sector in two-Higgs-Doublet-Models. Only a slight improvement in the experimental bound will exclude the region in the Supersymmetric Higgs parameter space which is inaccessible to collider searches.Comment: 8 pages plus 3 figures (available by request), latex, ANL-HEP-PR-92-110. Substantial revision to text, results unchange

    The Coulomb law in the pure gauge U(1) theory on a lattice

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    We study the heavy charge potential in the Coulomb phase of pure gauge compact U(1) theory on the lattice. We calculate the static potential VW(T,R)V_W(T,{\vec R}) from Wilson loops on a 163×3216^3 \times 32 lattice and compare with the predictions of lattice perturbation theory. We investigate finite size effects and, in particular, the importance of non-Coulomb contributions to the potential. We also comment on the existence of a maximal coupling in the Coulomb phase of pure gauge U(1) theory.Comment: 14 pages. LaTeX file and 3 postscript figure

    The Relationship Between Depressive Symptoms and Social Cognitive Processing in Partners of Long-Term Breast Cancer Survivors

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    Purpose/Objectives: To determine 1) if depressive symptoms in partners of long-term breast cancer survivors (BCS) could be predicted by social cognitive processing theory, and 2) if partners of younger and older breast cancer survivors were differentially affected by the cancer experience. Design: A cross-sectional, descriptive study utilizing self-report questionnaires. Setting: Indiana University and 97 ECOG-ACRIN sites. Sample: Partners of breast cancer survivors (n=508) diagnosed 3-8 years prior. Methods: Secondary data mediation analyses were conducted to determine if cognitive processing mediated the relationship between social constraints and depressive symptoms. Age-related differences on all scales were tested. Main Research Variables: Depressive symptoms; secondary variables included social constraints, cognitive processing (avoidance and intrusive thoughts), and potentially confounding variables. Findings: Cognitive processing mediated the relationship between social constraints and depressive symptoms for partners (F(5,498)= 19.911, R2=.167, p<.001). Partners of young BCS reported worse outcomes on all measures than partners of older breast cancer survivors Conclusions: As predicted by the social cognitive processing theory, cognitive processing mediated the relationship between social constraints and depressive symptoms. Furthermore, partners of younger BCS fared worse on social constraints, intrusive thoughts and depressive symptoms than partners of older BCS. Implications for Nursing: Results provide support for using the social cognitive processing theory in intervention design with partners of long-term BCS to decrease depressive symptoms. Knowledge Translation: • Partners of long-term BCS report clinically significant depression. • Partners of younger BCS report higher levels of depressive symptoms than the national average and than partners of older survivors. • Addressing social constraints within the dyad may improve depressive symptoms.This study was coordinated by the ECOG-ACRIN Cancer Research Group (Robert L. Comis, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported in part by Public Health Service Grants CA189828, CA180795, CA37403, CA35199, CA17145 and CA49883, and from the National Cancer Institute, National Institutes of Health and the Department of Health and Human Services. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute. Research reported in this publication was supported by the National Institute of Nursing Research of the National Institutes of Health under Award Number F31NR013822, and by the National Cancer Institute of the National Institutes of Health under Award Numbers K05CA175048 and R25CA117865. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health, including the National Cancer Institute or the National Institute of Nursing Research

    The bsγγb\to s\gamma\gamma transition in softly broken supersymmetry

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    We study the effect of supersymmetric contributions to the effective quark transition bsγγb\to s\gamma\gamma, including leading order QCD effects. We apply the discussion to the decay BsγγB_s\to\gamma\gamma. Even though one-particle irreducible contributions could play a role, numerical cancelations make the amplitude for the two-photon emission strongly correlated to the bsγb\to s\gamma amplitude which is sharply constrained by experiment. A quite general statement follows: as long as non-standard physics effects appear only in the matching of the Wilson coefficients of the standard effective operator basis, the deviations from the standard model expectations of the decay rates induced by bsγγb\to s\gamma\gamma are bound to follow closely the corresponding deviations on bsγb\to s\gamma. Effects of new physics are therefore bound to be small.Comment: Latex2e, RevTex, 22 pages, 8 eps figures, comments and references adde

    Recalculation of QCD Corrections to bsγb \to s \gamma Decay

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    We give a more complete calculation of bsγb \to s\gamma decay, including leading log QCD corrections from mtopm_{top} to MWM_W in addition to corrections from MWM_{W} to mbm_b. We have included the full set of dimension-6 operators and corrected numerical mistakes of anomalous dimensions in a previous paper\cite{Cho}. Comparing with the calculations without QCD running from mtopm_{top} to MWM_W\cite{Mis}, the inclusive decay rate is found to be enhanced. At mt=150m_t=150GeV, it results in 12\% enhancement, and for mt=250m_t=250GeV, 15\% is found. The total QCD effect makes an enhanced factor of 4.2 at mt=150m_t=150GeV, and 3.2 for mt=250m_t=250GeV.Comment: 16 pages, 7 figures (uuencoded ps files), Changes of description. To appear in Phys. Rev.
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