3,779 research outputs found

    From the ISR to RHIC--measurements of hard-scattering and jets using inclusive single particle production and 2-particle correlations

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    Hard scattering in p-p collisions, discovered at the CERN ISR in 1972 by the method of leading particles, proved that the partons of Deeply Inelastic Scattering strongly interacted with each other. Further ISR measurements utilizing inclusive single or pairs of hadrons established that high pT particles are produced from states with two roughly back-to-back jets which are the result of scattering of constituents of the nucleons as desribed by Quantum Chromodynamics (QCD), which was developed during the course of these measurements. These techniques, which are the only practical method to study hard-scattering and jet phenomena in Au+Au central collisions at RHIC energies, are reviewed, as an introduction to present RHIC measurements.Comment: To appear in the proceedings of the workshop on Correlations and Fluctuations in Relativistic Nuclear Collisions, MIT, Cambridge, MA, April 21-23, 2005, 10 pages, 9 figures, Journal of Physics: Conference Proceeding

    Results from RHIC with Implications for LHC

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    Results from the PHENIX experiment at RHIC in p-p and Au+Au collisions are reviewed from the perspective of measurements in p-p collisions at the CERN-ISR which serve as a basis for many of the techniques used. Issues such as J/Psi suppression and hydrodynamical flow in A+A collisions require data from LHC-Ions for an improved understanding. Suppression of high pT particles in Au+Au collisions, first observed at RHIC, also has unresolved mysteries such as the equality of the suppression of inclusive pi0 (from light quarks and gluons) and direct-single electrons (from the decay of heavy quarks) in the transverse momentum range 4< pT < 9 GeV/c. This disfavors a radiative explanation of suppression and leads to a fundamental question of whether the Higgs boson gives mass to fermions. Observation of an exponential distribution of direct photons in central Au+Au collisions for 1< pT <2 GeV/c where hard-processes are negligible and with no similar exponential distribution in p-p collisions indicates thermal photon emission from the medium at RHIC, making PHENIX at the moment ``the hottest experiment in Physics''.Comment: Invited lectures at the International School of Subnuclear Physics, 47th Course, "The most unexpected at LHC and the status of High Energy Frontier'', Erice, Sicily, Italy, August 29-September 7. 2009. 32 pages, 22 figure

    Why the xE distribution triggered by a leading particle does not measure the fragmentation function but does measure the ratio of the transverse momenta of the away-side jet to the trigger-side jet

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    Hard-scattering of point-like constituents (or partons) in p-p collisions was discovered at the CERN-ISR in 1972 by measurements utilizing inclusive single or pairs of hadrons with large transverse momentum (pTp_T). It was generally assumed, following Feynman, Field and Fox, as shown by data from the CERN-ISR experiments, that the pTap_{T_a} distribution of away side hadrons from a single particle trigger [with pTtp_{T_t}], corrected for of fragmentation would be the same as that from a jet-trigger and follow the same fragmentation function as observed in e+e−e^+ e^- or DIS. PHENIX attempted to measure the fragmentation function from the away side xE∼pTa/pTtx_E\sim p_{T_a}/p_{T_t} distribution of charged particles triggered by a π0\pi^0 in p-p collisions at RHIC and showed by explicit calculation that the xEx_E distribution is actually quite insensitive to the fragmentation function. Illustrations of the original arguments and ISR results will be presented. Then the lack of sensitivity to the fragmentation function will be explained, and an analytic formula for the xEx_E distribution given, in terms of incomplete Gamma functions, for the case where the fragmentation function is exponential. The away-side distribution in this formulation has the nice property that it both exhibits xEx_E scaling and is directly sensitive to the ratio of the away jet p^Ta\hat{p}_{T_a} to that of the trigger jet, p^Tt\hat{p}_{T_t}, and thus can be used, for example, to measure the relative energy loss of the two jets from a hard-scattering which escape from the medium in A+A collisions. Comparisons of the analytical formula to RHIC measurements will be presented, including data from STAR and PHENIX, leading to some interesting conclusions.Comment: 6 pages, 5 figures, Proceedings of Poster Session, 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2006), November 14-20, 2006, Shanghai, P. R. Chin

    Analyzing a Freudian analysis.

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    Effectiveness of continence promotion for older women via community organisations: A cluster randomised trial

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    This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/3.0/Objectives: The primary objective of this cluster randomised controlled trial was to compare the effectiveness of the three experimental continence promotion interventions against a control intervention on urinary symptom improvement in older women with untreated incontinence recruited from community organisations. A second objective was to determine whether changes in incontinence-related knowledge and new uptake of risk-modifying behaviours explain these improvements. Setting: 71 community organisations across the UK. Participants: 259 women aged 60 years and older with untreated incontinence entered the trial; 88% completed the 3-month follow-up. Interventions: The three active interventions consisted of a single 60 min group workshop on (1) continence education (20 clusters, 64 women); (2) evidence-based self-management (17 clusters, 70 women); or (3) combined continence education and self-management (17 clusters, 61 women). The control intervention was a single 60 min educational group workshop on memory loss, polypharmacy and osteoporosis (17 clusters, 64 women). Primary and secondary outcome measures: The primary outcome was self-reported improvement in incontinence 3 months postintervention at the level of the individual. The secondary outcome was change in the International Consultation on Incontinence Questionnaire (ICIQ) from baseline to 3-month follow-up. Changes in incontinence-related knowledge and behaviours were also assessed. Results: The highest rate of urinary symptom improvement occurred in the combined intervention group (66% vs 11% of the control group, prevalence difference 55%, 95% CI 43% to 67%, intracluster correlation 0). 30% versus 6% of participants reported significant improvement respectively (prevalence difference 23%, 95% CI 10% to 36%, intracluster correlation 0). The number-needed-to-treat was 2 to achieve any improvement in incontinence symptoms, and 5 to attain significant improvement. Compared to controls, participants in the combined intervention reported an adjusted mean 2.05 point (95% CI 0.87 to 3.24) greater improvement on the ICIQ from baseline to 3-month follow-up. Changes in knowledge and self-reported risk-reduction behaviours paralleled rates of improvement in all intervention arms. Conclusions: Continence education combined with evidence-based self-management improves symptoms of incontinence among untreated older women. Community organisations represent an untapped vector for delivering effective continence promotion interventions.Canadian Institutes of Health Research – Institute on Aging and the Economic and Social Research Council (UK

    Mass-preserving maps for registration and visual tracking

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    A fundamental test of the Higgs Yukawa coupling at RHIC in A+A collisions

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    Searches for the intermediate boson, W±W^{\pm}, the heavy quantum of the Weak Interaction, via its semi-leptonic decay, W→e+νW\to e +\nu, in the 1970's instead discovered unexpectedly large hadron production at high pTp_T, notably π0\pi^0, which provided a huge background of e±e^{\pm} from internal and external conversions. Methods developed at the CERN ISR which led to the discovery of direct-single-e±e^{\pm} in 1974, later determined to be from the semi-leptonic decay of charm which had not yet been discovered, were used by PHENIX at RHIC to make precision measurements of heavy quark production in p-p and Au+Au collisions, leading to the puzzle of apparent equal suppression of light and heavy quarks in the QGP. If the Higgs mechanism gives mass to gauge bosons but not to fermions, then a proposal that all 6 quarks are nearly massless in a QGP, which would resolve the puzzle, can not be excluded. This proposal can be tested with future measurements of heavy quark correlations in A+A collisionsComment: 12 pages, 16 figures, 26th Winter Workshop on Nuclear Dynamics, Ocho Rios, Jamaica WI, January 2-9, 2010. Corrected citation of 1974 direct single lepton discover

    Mucocutaneous disease and related clinical characteristics in hospitalized children and adolescents with COVID-19 and multisystem inflammatory syndrome in children.

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    Background Little is known about mucocutaneous disease in acutely ill children and adolescents with COVID-19 and multisystem inflammatory syndrome in children (MIS-C). Objective To characterize mucocutaneous disease and its relation to clinical course among hospitalized patients with COVID-19 and MIS-C. Methods Descriptive cohort study of prospectively and consecutively hospitalized eligible patients between May 11, 2020 and June 5, 2020. Results In COVID-19 patients, 4 of 12 (33%) had rash and/or mucositis, including erythema, morbilliform pattern, and lip mucositis. In MIS-C patients, 9 of 19 (47%) had rash and/or mucositis, including erythema, morbilliform, retiform purpura, targetoid and urticarial patterns, along with acral edema, lip mucositis, tongue papillitis, and conjunctivitis. COVID-19 patients with rash had less frequent respiratory symptoms, pediatric intensive care unit admission, invasive ventilation, and shorter stay versus COVID-19 patients without rash. MIS-C patients with rash had less frequent pediatric intensive care unit admission, shock, ventilation, as well as lower levels of C-reactive protein, ferritin, D-dimer, and troponin (vs MIS-C without rash). Neutrophil-to-lymphocyte ratio was similar for patients with and without rash in both groups. None of the MIS-C patients met criteria for Kawasaki disease. Limitations Small sample sizes. Conclusions Mucocutaneous disease is common among children and adolescents with COVID-19 and MIS-C. Laboratory trends observed in patients with rash may prognosticate a less severe course

    A compilation, classification, and comparison of lists of spontaneous speaking vocabulary of children in kindergarten, Grade I, Grade II, and Grade III

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    Thesis (Ed.M.)--Boston UniversityLanguage development has been studied for many years. The beginning vocabularies are easy to count ana record. As tne child grows and moves about, his speaking vocabulary increases very rapidly. Some estimates suggest that a minimum speaking vocabulary at six years would include three thousand words. New words have come into children's speaking vocabularies as a result of modern technology since World War II. Lists of spontaneous vocabulary furnish material for teachers and text book writers. The purpose of this study is to analyze two lists recorded in 1954 and 1955. An attempt has been made to classify the new list. The lists were compared with three existing lists, Rinsland, International Kindergarten Union and Gates

    Transverse momentum fluctuations and percolation of strings

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    The behaviour of the transverse momentum fluctuations with the centrality of the collision shown by the Relativistic Heavy Ion Collider data is naturally explained by the clustering of color sources. In this framework, elementary color sources --strings-- overlap forming clusters, so the number of effective sources is modified. These clusters decay into particles with mean transverse momentum that depends on the number of elementary sources that conform each cluster, and the area occupied by the cluster. The transverse momentum fluctuations in this approach correspond to the fluctuations of the transverse momentum of these clusters, and they behave essentially as the number of effective sources.Comment: 16 pages, RevTex, 4 postscript figures. Enhanced version. New figure
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