Jet Physics at the Tevatron

Recent analyses by the CDF and D0 Collaborations of jet data produced in proton-antiproton collisions at the Fermilab Tevatron Collider are presented. These include new studies of the inclusive jet production cross section, a measurement of the strong coupling constant, the first measurement of subjet multiplicity of quark and gluon jets, examination of ratios of multijet cross sections and their implications for choice of renormalization scale, and a study of charged jet evolution and energy flow in the underlying event. The results are compared to theoretical predictions.Comment: Proceedings of the XXXVII Rencontres de Moriond: QCD and High Energy Hadronic Interaction

Effect of Temperature and Charged Particle Fluence on the Resistivity of Polycrystalline CVD Diamond Sensors

The resistivity of polycrystalline chemical vapor deposition diamond sensors is studied in samples exposed to fluences relevant to the environment of the High Luminosity Large Hadron Collider. We measure the leakage current for a range of bias voltages on samples irradiated with 800 MeV protons up to 1.6\times 10^{16} p/cm^2. The proton beam at LANSCE, Los Alamos National Laboratory, was applied to irradiate the samples. The devices' resistivity is extracted for temperatures in the -10^\circC to +20^\circC range.Comment: 13 pages, 8 figure

Inclusive Jets at the Tevatron

Results are presented for the inclusive jet cross section versus jet transverse energy in proton-antiproton collisions at center of mass energy 1.8 TeV as measured by the CDF and D0 detectors at Fermilab's Tevatron collider. The data are compared to next-to-leading order QCD predictions using different input parton distribution functions. The ratio of inclusive jet cross sections at center of mass energy 0.63 TeV and center of mass energy 1.8 TeV, versus jet x_T, is also presented and compared to QCD predictions.Comment: Submitted to the proceedings of the XXIX International Symposium on Multiparticle Dynamics (ISMD99), Providence, RI. 12 pages including 12 figure

Heavy Quark Production at the Tevatron

Results are presented from four CDF analyses involving heavy quark production in proton-antiproton collisions at center of mass energy 1.96 TeV. The shapes of b-jets are found to be broader than inclusive predictions and broader than both PYTHIA and HERWIG defaults. A measurement of the production cross section for psi(2S) is consistent with Run 1 results and with theoretical predictions associated with parton distribution function energy dependence. The inclusive b-jet production cross section is also consistent with theoretical predictions over six orders of magnitude. The b-bbar differential production cross section is compared to several theoretical models and found to be best described by MC@NLO + JIMMY.Comment: ICHEP08, 5 figure

ATLAS Pixel Radiation Monitoring with HVPP4 System

In this talk we present the basis for the protocol for radiation monitoring of the ATLAS Pixel Sensors. The monitoring is based on a current measurement system, HVPP4. The status on the ATLAS HVPP4 system development is also presented.Comment: Talk given at DPF-2009, Detroit, MI, July 2009; 8 pages, 4 figures, 6 tables; To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Comparison of Three-jet Events in Proton-Antiproton Collisions at sqrt{s}=1.8 TeV to Predictions from a Next-to-leading Order QCD Calculation

The properties of three-jet events with total transverse energy greater than 320 GeV and individual jet energy greater than 20 GeV have been analyzed and compared to absolute predictions from a next-to-leading order (NLO) perturbative QCD calculation. These data, of integrated luminosity 86 pb^-1, were recorded by the CDF Experiment for proton-antiproton collisions at sqrt{s}=1.8 TeV. This study tests a model of higher order QCD processes that result in gluon emission and can be used to estimate the magnitude of the contribution of processes higher than NLO. The total cross section is measured to be 466 \pm 3(stat.)^{+207}_{-70}(syst.) pb. The differential cross section is furthermore measured for all kinematically accessible regions of the Dalitz plane, including those for which the theoretical prediction is unreliable. While the measured cross section is consistent with the theoretical prediction in magnitude, the two differ somewhat in shape in the Dalitz plane.Comment: For the CDF Collaboration. Contributed to the proceedings of the Eleventh High-Energy Physics International Conference on QCD, Montpellier, France, July 200

Capacitance of Silicon Pixels

Capacitance measurements have been made on silicon pixel sensors of types n+ on n, p+ on n, and n+ on p. The arrays test a variety of implant and gap widths, and the n+ on n devices test several p-stop designs. The measurements examine inter-pixel and backplane contributions and include studies of temperature dependence. Measurements were made before and after irradiation with fluences relevant to LHC experiments and Fermilab Tevatron Run 2.Comment: 28 pages including 22 figure

Student teachers' impressions of primary design and technology in English schools: a pilot study

This paper arose from a joint Nuffield Foundation and Design and Technology Association seminar in February 2002. One of the recommendations was that primary initial teacher education (ITE) trainers, together with teachers in schools, would use their normal working activities to generate data that can be used as the basis for academic papers. Initially it provides the background to the present research project, focusing on concerns regarding the position and status of design and technology in English primary schools since the introduction of D&T as a compulsory subject of the National Curriculum in 1990. As a result of the seminar a group of ITE providers in South East England from the University of Brighton; Canterbury Christ Church University; Goldsmiths, University of London; Roehampton University and St Mary’s College, Twickenham first met in the Summer of 2004. The aim of the research was to develop a clearer understanding of the position and character of D&T in each ITE provider’s partner schools. Each provider piloted a questionnaire, developed by the group, in 2004-2005 to gather data of primary student teachers’ impressions of D&T and working practices in their placement schools. The paper presents a summary of data from individual institutions and attempts to analyse and highlight some common key issues across the ITE providers. Finally, the paper draws some conclusions from the research and considers their implications for the planning and teaching of the ITE providers’ courses and partnership links with schools in the future. The paper concludes by considering ideas for further research

A Roadmap for HEP Software and Computing R&D for the 2020s

Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.Peer reviewe