Phys Rev Lett
September 2011
We present a measurement of the ratio of top quark branching fractions R=B(t→Wb)/B(t→Wq), where q can be a d, s, or b quark, in the lepton+jets and dilepton tt final states. The measurement uses data from 5.4 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider.
View Article and Find Full Text PDFWe report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb(-1). This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanβ.
View Article and Find Full Text PDFPhys Rev Lett
September 2011
A search for three-jet hadronic resonance production in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb(-1). Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed using a signature-based approach. The number of expected standard model background events is found to be in good agreement with the observed events.
View Article and Find Full Text PDFElectroweak production of the top quark is measured for the first time in pp collisions at √=7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb⁻¹. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data.
View Article and Find Full Text PDFWe measure the top quark mass (m(t)) in p ̄p collisions at a center of mass energy √s = 1.96 TeV using dilepton t ̄t→W(+)bW(-) ̄b→ℓ(+)ν(ℓ)bℓ(-) ̄ν(ℓ) ̄b events, where ℓ denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.
View Article and Find Full Text PDFPhys Rev Lett
August 2011
We present a search for pair production of a fourth generation t' quark and its antiparticle, followed by their decays to a W boson and a jet, based on an integrated luminosity of 5.3 fb(-1) of proton-antiproton collisions at √s = 1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider.
View Article and Find Full Text PDFObjective: To report the clinical, electroencephalographic, and neuroradiologic findings in a kindred with a novel insertion in the prion protein gene, PRNP.
Design: Clinical description of a kindred.
Setting: Mayo Clinic Alzheimer Disease Research Center (Rochester, Minnesota).
A comparison of the relative yields of Υ resonances in the μ(+)μ(-) decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4 GeV/c and pseudorapidity below 2.
View Article and Find Full Text PDFJ Health Care Poor Underserved
August 2011
Few studies have examined barriers and facilitators to colorectal cancer (CRC) screening among Hispanics, particularly sociocultural factors that may be relevant. This paper examines the influence of sociocultural factors on adherence to fecal occult blood testing (FOBT) and colonoscopy. A survey was conducted among a sample of 400 low-income Hispanics in East Harlem, New York.
View Article and Find Full Text PDFWe determine the fraction of tt events with spin correlation, assuming that the spin of the top quark is either correlated with the spin of the top antiquark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study tt spin correlation. We use tt → W+ b W- b → ℓ+ νbℓ- ν b final states produced in pp collisions at a center-of-mass energy sqrt(s)=1.
View Article and Find Full Text PDFA first measurement of the polarization of W bosons with large transverse momenta in pp collisions is presented. The measurement is based on 36 pb⁻¹ of data recorded at √s = 7 TeV by the CMS detector at the LHC. The left-handed, right-handed, and longitudinal polarization fractions (f(L), f(R), and f₀, respectively) of W bosons with transverse momenta larger than 50 GeV are determined by using decays to both electrons and muons.
View Article and Find Full Text PDFWe present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W boson in data corresponding to an integrated luminosity of 4.3 fb(-1) collected with the D0 detector at √s = 1.96 TeV.
View Article and Find Full Text PDFWe search for resonant WW or WZ production by using up to 5.4 fb(-1) of integrated luminosity collected by the D0 experiment in run II of the Fermilab Tevatron Collider. The data are consistent with the standard model background expectation, and we set limits on a resonance mass by using the sequential standard model W' boson and the Randall-Sundrum model graviton G as benchmarks.
View Article and Find Full Text PDFA search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 36 pb(-1) recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs.
View Article and Find Full Text PDFTo better understand the role of bats as reservoirs of Bartonella spp., we estimated Bartonella spp. prevalence and genetic diversity in bats in Guatemala during 2009.
View Article and Find Full Text PDFHypertension can lead to cardiovascular diseases and other chronic conditions. While the impact of hypertension on premature death and life expectancy has been published, the impact on health-adjusted life expectancy has not, and constitutes the research objective of this study. Health-adjusted life expectancy (HALE) is the number of expected years of life equivalent to years lived in full health.
View Article and Find Full Text PDFA search for supersymmetry in the context of general gauge-mediated breaking with the lightest neutralino as the next-to-lightest supersymmetric particle and the gravitino as the lightest is presented. The data sample corresponds to an integrated luminosity of 36 pb(-1) recorded by the CMS experiment at the LHC. The search is performed by using events containing two or more isolated photons, at least one hadronic jet, and significant missing transverse energy.
View Article and Find Full Text PDFThe present analysis sought to determine the usefulness and validity of the Short Acculturation Scale for Hispanics (SASH) in assessment of acculturation among Hispanics participating in a colorectal cancer screening study. Primary data was collected from 2008 to 2009 through surveys in East Harlem community-based sites and health clinics among Hispanics. Bivariate correlations and independent samples t tests assessed SASH correlation with acculturation proxies and relationships between proxies, SASH, and sociodemographics.
View Article and Find Full Text PDFPhysiother Theory Pract
November 2011
The purpose of this investigation was to examine the intrasession and interrater reliability of rehabilitative ultrasound imaging (RUSI) to measure the deep neck flexors (DNF). Two investigators traced the DNF muscle borders in eight female subjects aged 33 ± 11.2 years.
View Article and Find Full Text PDFDijet angular distributions are measured over a wide range of dijet invariant masses in pp collisions at √s = 7 TeV, at the CERN LHC. The event sample, recorded with the CMS detector, corresponds to an integrated luminosity of 36 pb⁻¹. The data are found to be in good agreement with the predictions of perturbative QCD, and yield no evidence of quark compositeness.
View Article and Find Full Text PDFA search for pair production of second-generation scalar leptoquarks in the final state with two muons and two jets is performed using proton-proton collision data at √s = 7 TeV collected by the CMS detector at the LHC. The data sample used corresponds to an integrated luminosity of 34 pb⁻¹. The number of observed events is in good agreement with the predictions from the standard model processes.
View Article and Find Full Text PDFA search for pair production of first-generation scalar leptoquarks is performed in the final state containing two electrons and two jets using proton-proton collision data at √s = 7 TeV. The data sample used corresponds to an integrated luminosity of 33 pb⁻¹ collected with the CMS detector at the CERN LHC. The number of observed events is in good agreement with the predictions for the standard model background processes, and an upper limit is set on the leptoquark pair production cross section times β² as a function of the leptoquark mass, where β is the branching fraction of the leptoquark decay to an electron and a quark.
View Article and Find Full Text PDFWe present a search for the standard model Higgs boson (H) in pp collisions at sqrt(s)=1.96 TeV in events containing a charged lepton (ℓ), missing transverse energy, and at least two jets, using 5.4 fb(-1) of integrated luminosity recorded with the D0 detector at the Fermilab Tevatron Collider.
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