2,384 research outputs found

    Review of W and Z Production at the Tevatron

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    The CDF and \D0 collaborations have used recent data taken at the Tevatron to perform QCD tests with WW and ZZ bosons decaying leptonically. \D0 measures the production cross section times branching ratio for WW and ZZ bosons. This also gives an indirect measurement of the total width of the WW boson: \gw=2.126\pm0.092 GeV. CDF reports on a direct measurement of \gw=2.19\pm0.19 GeV, in good agreement with the indirect determination and Standard Model predictions. \D0's measurement of the differential dσ/dpTd\sigma/dp_T distribution for WW and ZZ bosons decaying to electrons agrees with the combined QCD perturbative and resummation calculations. In addition, the dσ/dpTd\sigma/dp_T distribution for the ZZ boson discriminates between different vector boson production models. Studies of W+JetW+ Jet production at CDF find the NLO QCD prediction for the production rate of W+1JetW+\ge1 Jet events to be in good agreement with the data.Comment: 8 pages, 6 figures, presented at XXXIIIrd Recontres de Moriond, QCD AND HIGH ENERGY HADRONIC INTERACTIONS,Les Arcs, Savoie, France, 199

    LHC Highlights and Prospects

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    These lectures were presented at the 2019 CERN Latin-American School of High Energy Physics. They were centered on the experimental methods used in hadron colliders to advance our understanding in the field of high energy particle physics. From accelerators, to particle detector technologies, object identification and data analyses techniques, the lectures did not attempt to provide a comprehensive, in-depth technical background, but rather focused on an overview of experimental techniques that enabled our advances in supporting and challenging the predictions of the standard model. This document includes a selection of the material presented in the lectures, focusing on how advances in detector technologies and object identification enabled the development of increasingly sophisticated data analysis techniques. This writeup also includes an outlook to the future LHC program and beyond.Comment: 38 pages, 31 figures, Lecture notes for the 10th CERN Latin-American School of High-Energy Physics (CLASHEP2019), 13 to 26 March 2019 in Villa General Belgrano, Cordoba Province, Argentin

    Observation of Single Top Quark Production

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    I report on the observation of electroweak production of single top quarks in proton anti-proton collisions at a center of mass energy of 1.96 TeV using 2.3 inverse-fb of data collected with the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon, missing transverse energy, two, three or four jets, with one or two of them identified as originating from the fragmentation of a b quark, the measured cross section for the process (pp-bar to tb+X,tqb+X) is 3.94 +- 0.88 pb (for a top quark mass of 170 GeV). The probability to measure a cross section at this value or higher in the absence of signal is 2.5E-7, corresponding to a 5.0 standard deviation significance. Using the same dataset, the measured cross sections for the t- and the s-channel processes when determined simultaneously with no assumption on their relative production rate are 3.14+0.94-0.80 pb and 1.05+-0.81pb respectively, consistent with standard model expectations. The measured t-channel cross section has a significance of 4.8 standard deviations, representing the first evidence for the production of an individual single top process to be detected.Comment: 8 pages, 8 figures, To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

    Metastatic eccrine porocarcinoma: report of a case and review of the literature

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    Eccrine porocarcinoma (EPC) is a rare type of skin cancer arising from the intraepidermal portion of eccrine sweat glands or acrosyringium, representing 0.005-0.01% of all cutaneous tumors. About 20% of EPC will recur and about 20% will metastasize to regional lymph nodes. There is a mortality rate of 67% in patients with lymph node metastases. Although rare, the occurrence of distant metastases has been reported

    Mutations in MITF and PAX3 Cause “Splashed White” and Other White Spotting Phenotypes in Horses

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    During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The “splashed white” pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes

    CMS physics technical design report : Addendum on high density QCD with heavy ions

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    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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