Fast Simulation of the CMS Detector

The CMS collaboration has developed a fast Monte Carlo simulation of the CMS detector with event production rates 100-1000 times faster than the GEANT4-based simulation, with comparable accuracy. This paper discusses the simulation of particle propagation in the CMS detector and the response of the different parts of the detector: the silicon tracker, the electromagnetic calorimeter, the hadronic calorimeter and the muon system

Reconstructing top quark-antiquark events with one lost jet

We present a technique for reconstructing the kinematics of pair-produced top quarks that decay to a charged lepton, a neutrino and four final state quarks in the subset of events where only three jets are reconstructed. We present a figure of merit that allows for a fair comparison of reconstruction algorithms without requiring their calibration. The new reconstruction of events with only three jets is fully competitive with the full reconstruction typically used for four jet events

New Limits on Local Lorentz Invariance in Mercury and Cesium

We report new bounds on Local Lorentz Invariance (LLI) violation in Cs and Hg. The limits are obtained through the observation of the the spin- precession frequencies of 199Hg and 133Cs atoms in their ground states as a function of the orientation of an applied magnetic field with respect to the fixed stars. We measure the amplitudes of the dipole couplings to a preferred direction in the equatorial plane to be 19(11) nHz for Hg and 9(5) microHz for Cs. The upper bounds established here improve upon previous bounds by about a factor of four. The improvement is primarily due to mounting the apparatus on a rotating table. New bounds are established on several terms in the standard model extension including the first bounds on the spin-couplings of the neutron and proton to the z direction, <7e-30 GeV and <7e-29 GeV, respectively.Comment: 17 pages, 6 figure

1914-05-25, Kenneth to Marion

This collection contains correspondence from PFC. Kenneth Kenyan Orbaker, USA, to his friend Marion Miller before the First World War. Orbaker was a member of the Intelligence Section, Headquarters Company, 309th Infantry during the First World War.https://digitalcommons.chapman.edu/kkorbaker_correspondence/1000/thumbnail.jp

External and Turbomachinery Flow Control Working Group

Broad Flow Control Issues: a) Understanding flow physics. b) Specific control objective(s). c) Actuation. d) Sensors. e) Integrated active flow control system. f) Development of design tools (CFD, reduced order models, controller design, understanding and utilizing instabilities and other mechanisms, e.g., streamwise vorticity)

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

A survey of Chautauqua county secondary teachers' perceptions of culturally and linguistically diverse students and teacher practices

1 online resource (ii, 75 pages) : illustrations.The purpose of this study was to investigate the perceptions secondary education teachers had about students from culturally and linguistically diverse (CALD) backgrounds, as well as their perceptions on culturally relevant practices (CRP) in their classrooms and curriculums. This study used an electronic survey which consisted of a total of 14 items and a Likert type scale that addressed teacher attitudes towards CALD students and CRP in the classroom. The participants included 61 middle and high school level teachers in Chautauqua County schools. Findings determined that teachers generally agreed that CALD home culture affects academic performance. However, teachers did not agree whether CALD students were disadvantaged specifically because of their home cultures. Based on these results, teachers understand that it is their responsibility for adapting curriculum to suit CALD student needs. [from author's abstract]SUNY at Fredoni

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

Measurement of Leptonic Asymmetries and Top Quark Polarization in ttbar Production

We present measurements of lepton (l) angular distributions in ttbar -> W+ b W- b -> l+ nu b l- nubar bbar decays produced in ppbar collisions at a center-of-mass energy of sqrt(s)=1.96TeV, where l is an electron or muon. Using data corresponding to an integrated luminosity of 5.4fb^-1, collected with the D0 detector at the Fermilab Collider, we find that the angular distributions of l- relative to anti-protons and l+ relative to protons are in agreement with each other. Combining the two distributions and correcting for detector acceptance we obtain the forward-backward asymmetry A^l_FB = (5.8 +- 5.1(stat) +- 1.3(syst))%, compared to the standard model prediction of A^l_FB (predicted) = (4.7 +- 0.1)%. This result is further combined with the measurement based on the analysis of the l+jets final state to obtain A^l_FB = (11.8 +- 3.2)%. Furthermore, we present a first study of the top-quark polarization.Comment: submitted versio