15,654 research outputs found
Prompt photon processes in photoproduction at HERA
We present results for the photoproduction of inclusive prompt photons and
for prompt photons accompanied by jets, measured with the ZEUS detector at
HERA. Cross sections as a function of pseudorapidity and transverse energy are
presented for 5 5 GeV in the centre of mass
energy range 120-270 GeV. Comparisons are made with predictions from leading
logarithm parton shower Monte Carlos and next-to-leading order QCD calculations
using currently available models of the photon structure. NLO QCD calculations
describe the shape and magnitude of the measurements reasonably well.Comment: Talk given at Photon99 Conference, Freiburg, German
Particle and Nuclear Physics with High Energy Leptons
In high centre-of-mass energy lepton-nucleon collisions the space-time time
resolution of partonic processes can be {\it fine-tuned} within a dynamical
range which is unattainable in hadronic collisions. Replacing nucleons by
nuclei of variable atomic number enables one to tune the strength of colour
forces. The experimental program of high energy electron-nucleon and its
extension to electron-nucleus collisions should thus give an unique opportunity
to experimentally explore the transition between the soft and hard interactions
of small and extended partonic systems. Such an experimental program, which can
be realized at DESY and/or BNL with relatively modest cost, is discussed in
this talk.Comment: Plenary talk at the PANIC conference, Uppsala, June 1999. 8 pages. 3
figure
Description of elastic vectormeson production and F_2 by two pomerons
Using the Model of the Stochastic Vacuum many diffractive processes have been
calculated by investigating the dipole-dipole scattering at a cm-energy of 20
GeV. In this work we extend the calculation to larger energies and small
dipoles. We assume that there are two pomerons, the hard- and the soft-pomeron,
which cause the different energy dependence for processes dominated by small or
large dipoles. The physical processes are obtained by smearing the
dipole-dipole amplitude with wavefunctions. For small dipoles the leading
perturbative contribution is taken into account. By that way we can describe in
addition to the already calculated low energy results (20 GeV) also the HERA
data for the considered processes in nearly the whole energy and Q^2 range.Comment: LaTeX2e, 4pp, espcrc2mod.sty (appended, espcrc2 with corrected
error), graphicx.sty, 17 eps-figures. Talk presented at QCD98, Montpellier,
France (Nucl.Phys.B Proc.Suppl.
How Increased Motivation Levels Can Lead to Increased Cardiovascular Endurance and Muscular Strength
The purpose of physical education programs in schools across the nation is to make students who pass the class into “physically educated” students; hence, the name of the class. A physically educated student possesses a set of characteristics developed by repeated exposure to effective physical education environments. One of the most important qualities a physically educated student possesses is that they “value physical activity and its contributions to a healthy lifestyle.” However, when high school students on the brink of adulthood do not possess attitudes that value regular physical activity, the goal of the physical education class becomes harder to reach. Through differentiation of physical education curriculum, teachers can increase levels of student autonomy, therefore increasing their motivation to participate in regular physical activity. A NASPE questionnaire can be administered to the class in order to gather a baseline reading of their motivation levels before a strength and conditioning unit begins. After both the educator and the students have completed the differentiated curriculum and physical activities, the questionnaire can be administered again. By comparing the results of the post-instruction motivational questionnaire and the recorded progress of each student on individual fitness logs, the effectiveness of the differentiated curriculum may be assessed
Isomorph-free generation of 2-connected graphs with applications
Many interesting graph families contain only 2-connected graphs, which have
ear decompositions. We develop a technique to generate families of unlabeled
2-connected graphs using ear augmentations and apply this technique to two
problems. In the first application, we search for uniquely K_r-saturated graphs
and find the list of uniquely K_4-saturated graphs on at most 12 vertices,
supporting current conjectures for this problem. In the second application, we
verifying the Edge Reconstruction Conjecture for all 2-connected graphs on at
most 12 vertices. This technique can be easily extended to more problems
concerning 2-connected graphs.Comment: 15 pages, 3 figures, 4 table
Deep inelastic diffractive scattering at HERA
Recent high precision measurements of deep inelastic diffractive scattering
at HERA are presented in an increased region of phase space. Current models for
diffractive photon dissociation are compared to the data.Comment: 6 pages, 6 figures, talk presented at QCD03, Montpellier, France,
July 2-9, 200
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