432 research outputs found

    Non-perturbative effects and the resummed Higgs transverse momentum distribution at the LHC

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    We investigate the form of the non-perturbative parameterization in both the impact parameter (b) space and transverse momentum (p_T) space resummation formalisms for the transverse momentum distribution of single massive bosons produced at hadron colliders. We propose to analyse data on Upsilon hadroproduction as a means of studying the non-perturbative contribution in processes with two gluons in the initial state. We also discuss the theoretical errors on the resummed Higgs transverse momentum distribution at the LHC arising from the non-perturbative contribution.Comment: 22 pages, 10 figure

    Same-sign W pair production as a probe of double parton scattering at the LHC

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    We study the production of same-sign W boson pairs at the LHC in double parton interactions. Compared with simple factorised double parton distributions (dPDFs), we show that the recently developed dPDFs, GS09, lead to non-trivial kinematic correlations between the W bosons. A numerical study of the prospects for observing this process using same-sign dilepton signatures, including same-sign WWjj, di-boson and heavy flavour backgrounds, at 14 TeV centre-of-mass energy is then performed. It is shown that a small excess of same-sign dilepton events from double parton scattering over a background dominated by single scattering WZ(gamma*) production could be observed at the LHC.Comment: 14 pages, 8 figures. Added references, slight changes in the text

    Service Learning as Inquiry in an Undergraduate Science Course

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    To engage students in applying scientific process skills to real-world issues, we implemented a service-learning project model in our undergraduate introductory biology course for science majors. This model illustrates how we integrate inquiry inside and outside of the classroom through four steps: service, learning, classroom, and community. Out-of-class activities engaged students in serving the community (Service step) while deepening their learning experience beyond what they would learn in a classroom (Learning step). To connect the service-learning project with scientific process skills, students were asked to identify problems that our community partners were trying to solve, identify proposed solutions, and design ways to evaluate those solutions (Classroom step). Additionally, students connected their service-learning topic with core concepts in Biology. After their service, students used metrics to analyze their impact. Students then synthesized the connection between their service, learning, and classroom projects by presenting their findings to the scientific and lay communities through a poster session (Community step). Here we provide details of the model, recommendations, and examples for others to execute an inquiry-based service-learning project

    Soft gluon resummation for squark and gluino pair-production at hadron colliders

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    We report on the study of soft gluon effects in the production of squarks and gluinos at hadron colliders. Close to production threshold, the emission of soft gluon results in the appearence of large logarithmic corrections in the theoretical expressions. In order to resum these corrections at next-to-leading-logarithmic accuracy appropriate one-loop anomalous dimensions have to be calculated. We present the calculation of the anomalous dimensions for all production channels of squarks and gluinos and provide numerical predictions for the Tevatron and the LHC.Comment: 6 pages, talk given at RADCOR 2009 - 9th International Symposium on Radiative Corrections (Applications of Quantum Field Theory to Phenomenology) October 25-30 2009, Ascona, Switzerlan

    Education for persons with special needs: Polish and Russian experience

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    © Author(s).The beginning of the 21st century is marked by systemic, economic and social transformations in Poland and Russia, that significantly affected the education system, including the education for persons with special needs. This paper is an attempt to present synthetically the changes relating to persons with disabilities. The current state of the education for children and youth with special needs will be considered due to the new education system, legal regulations, the school population, type of disability of pupils and the kinds of schools they attend. Compulsory education, which includes the level of primary and lower secondary schools, will be subject to a separate analysis. The article presents significant systemic changes in Polish and Russian education and the state development strategy in the sphere of social policy towards persons with disabilities. The new documents are analyzed that have led to important changes in policy direction with serious consequences in terms of the structure and curriculum of inclusive education in both countries. The paper introduces a review of the changes in policy direction with serious consequences in terms of the structure and curriculum of education for persons with special needs. A key objective of the paper will be to examine the new approaches to education of disabled persons in Russia and Poland and the subsequent changes in it

    Supersymmetric top and bottom squark production at hadron colliders

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    The scalar partners of top and bottom quarks are expected to be the lightest squarks in supersymmetric theories, with potentially large cross sections at hadron colliders. We present predictions for the production of top and bottom squarks at the Tevatron and the LHC, including next-to-leading order corrections in supersymmetric QCD and the resummation of soft gluon emission at next-to-leading-logarithmic accuracy. We discuss the impact of the higher-order corrections on total cross sections and transverse-momentum distributions, and provide an estimate of the theoretical uncertainty due to scale variation and the parton distribution functions.Comment: 29 pages, 6 figure

    Snowmass 2001: Jet Energy Flow Project

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    Conventional cone jet algorithms arose from heuristic considerations of LO hard scattering coupled to independent showering. These algorithms implicitly assume that the final states of individual events can be mapped onto a unique set of jets that are in turn associated with a unique set of underlying hard scattering partons. Thus each final state hadron is assigned to a unique underlying parton. The Jet Energy Flow (JEF) analysis described here does not make such assumptions. The final states of individual events are instead described in terms of flow distributions of hadronic energy. Quantities of physical interest are constructed from the energy flow distribution summed over all events. The resulting analysis is less sensitive to higher order perturbative corrections and the impact of showering and hadronization than the standard cone algorithms.Comment: REVTeX4, 13 pages, 6 figures; Contribution to the P5 Working Group on QCD and Strong Interactions at Snowmass 200
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