790 research outputs found
Questions on uncertainties in parton distributions
No full textA discussion is presented of the manner in which uncertainties in parton distributions and related quantities are determined. One of the central problems is the criteria used to judge what variation of the parameters describing a set of partons is acceptable within the context of a global fit. Various ways of addressing this question are outlined. (From the workshop 'Advanced Statistical Techniques in Particle Physics', 18–22 March 2002
Including heavy quark production in ZEUS-PDF fits
No full textAt HERA heavy quarks may contribute up to 30% of the structure function F2. The potential of including heavy-quark data in the ZEUS PDF fits is explored, using D* double dierential cross-sections as well as the inclusive quantities Fcc2 , Fcc2 . The introduction of heavy quarks requires an extension of the DGLAP formalism. The effect of using different heavy avour number schemes, and different approaches to the running of αs, are compared
Extraction of the proton parton density functions using a NLO-QCD fit of the combined H1 and ZEUS inclusive dis cross sections
No full textThe combined HERA-I data set, of neutral and charged current inclusive cross-sections for e + p and e ¡ p scattering, is used as the sole input for a next-to-leading order (NLO) QCD parton distribution function (PDF) t. The consistent treatment of systematic uncertainties in the joint data set ensures that experimental uncertainties on the PDFs can be calculated without need for an increased  2 tolerance. This results in PDFs with greatly reduced experimental uncertainties compared to the separate analyses of the ZEUS and H1 experiments. Model uncertainties, including those arising from parametrization dependence, are also carefully considered. The resulting HERAPDFs have impressive precision compared to the global ts
Impact of and constraints on PDFs at the LHC
No full textUncertainties on parton distribution functions (PDFs) compromise discovery at the LHC for any new physics which can be described as a contact-interaction. PDF uncertainties also limit our ability to use W and Z cross-sections as anaccurate luminosity monitor. The impact of the current level of PDF uncertainty on LHC physics is reviewed and the possibility of reducing this uncertainty using LHC data is investigated
MEASUREMENT OF F(2) AND X F(3) DOWN TO LOW W**2 AND MEASUREMENT OF DYNAMICAL HIGHER TWIST CONTRIBUTIONS
No full textProtocol for the United Kingdom Rotator Cuff Study (UKUFF) : a randomised controlled trial of open and arthroscopic rotator cuff repair
No full textThis project was funded by the NIHR Health Technology Assessment programme (project number 05/47/02). J. L. Rees has received a grant from Oxford University which is related to this paper. J. Dawson reports that Oxford University has received a grant from HTA which is related to this paper, as well as a study grant.Peer reviewe
A QCD analysis of ZEUS data including DIS inclusive cross sections with longitudinally polarised leptons and data run at lower proton beam energies.
No full textNew ZEUS data are added into the NLO QCD analysis of the ZEUS-JETS PDF fit. The addition of high-Q2 NC and CC e- p inclusive cross-section data improves the determination of the u-valence quark at high x. The addition of high-Q2 CC e+p inclusive cross-section data improves the determination of the d-valence quark at high x. The addition of lower-Q2 NC e+ p inclusive cross-section data, run at three difierent proton beam energies, improves the determination of the sea and gluon PDFs at small x. The new PDF fit is called the ZEUS09 PDF fit
The rise and fall of F-2 at low x
No full textA short personal account is given of the impact of HERA data and the influence of Jan Kwiecinski on low x physics
Disparities in registration and use of an online patient portal among older adults: findings from the LitCog cohort
No full text(C) The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved.Financial disclosure: This project was supported by the
National Institute on Aging (R01 AG030611), the National
Center for Research Resources (5UL1RR025741), and the
National Center for Advancing Translational Sciences (Grant
8UL1TR000150). The content is solely the responsibility of the
authors and does not necessarily represent the official views of
the National Institutes of Health. Smith is currently supported
by a Cancer Research UK Fellowship
Summary of the activities of the structure function working group
No full textThe main areas covered in the sessions of the structure function working group are summarized as an introduction to the subsequent articles
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