117874733
Missing Transverse Energy Reconstruction in the ATLAS Calorimeter
A very good missing transverse energy (ETMiss) measurement is a crucial requirement for the study of many physics channels at the LHC, including but not limited to Standard Model W or top production, production of Higgs bosons decaying to taus, and SUSY events, for example. The most important contribution to this measurement in the ATLAS detector comes from the calorimeters, which provide near hermetic energy reconstruction up to pseudo‐rapidities of |eta|<5. The transverse energy components reconstructed in individual calorimeter cells and clusters of cells, in addition to corrections for losses in inactive materials and cracks, are the basis of the EtMiss calculation. Additional refinement can be achieved by including specific calibrations depending on calorimeter signal shapes used in hadronic calibration approaches, and/or identified particle and jet signals, for example, all applied at the level of the cell and cluster signals. In this talk we present comparisons between several different strategies ...
109825275
Design of the front-end analog electronics for the ATLAS tile calorimeter
Abstract We describe the design of the analog portion of an electronics system to process signals from the photomultiplier tubes of the ATLAS Tile Calorimeter. The system has a 16-bit dynamic range and is capable of measuring energy depositions in a single calorimeter cell from ∼ 20 MeV to ∼ 1.3 TeV . In order to maintain the calorimeter calibration at the 1% level the system includes a charge injection circuit and a current integrator for use with a cesium source system and with the time-averaged currents produced by the LHC. The system also provides a signal for an analog adder which produces an energy sum for each calorimeter tower. Over 10,000 channels of this system have been constructed and delivered for use.
121736823
Search of extra space dimensions with ATLAS
If extra spatial dimensions were to exist, they could provide a solution to the hierarchy problem. The studies done by the ATLAS Collaboration on the sensitivity of the detector to various extra dimension models are reported in this document.
179053911
W mass and width from LEP
We present a measurement of the mass and width of the W boson by direct reconstruction in the qqqq and qq ± ν channels by of the four LEP 2 experiments, ALEPH, DELPHI, L3 and OPAL. Each experiment used about 700 pb −1 of collected data. Major systematic uncertainties are discussed. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.
122845510
W Mass Measurement at Lep 2
The measurement of the W boson mass by the four Lep experiments, Aleph , Delphi , L3 and Opal , is presented. Particular emphasis is paid on the systematic uncertainties, which limits the precision of the present measurement.
57597970
ATLAS tile calorimeter interface
This paper describes the ATLAS Tile Calorimeter Digitizer-toRod Interface card design, performance and radiation hardness tests and production processes.
2625056
Hep Cluster First Step Towards Grid Computing
HEP Cluster is designed and implemented in Scientific Linux Cern 5.5 to grant High Energy Physics researchers one place where they can go to undertake a particular task or to provide a parallel processing architecture in which CPU resources are shared across a network and all machines function as one large supercomputer. It gives physicists a facility to access computers and data, transparently, without having to consider location, operating system, account administration, and other details. By using this facility researchers can process their jobs much faster than the stand alone desktop systems.
14566617
Behaviour of the centrifugal force and of ellipticity for a slowly rotating fluid configuration with different equations of state
We have evaluated the centrifugal force acting on a fluid element and the ellipticity of the fluid configuration, which is slowly rotating, using the Hartle - Thorne solution for different equations of state. The centrifugal force shows a maximum in every case, whereas the reversal in sign could be seen in only one case and the system becomes unstable in other cases. The ellipticity as calculated from the usual definition shows maxima, whereas the definition obtained from the equilibration of the inertial forces, shows a negative behaviour, indicating that the system is prolate and not oblate. This prolate shape of the configuration is similar to the one earlier found by Pfister and Braun for a rotating shell of matter, using the correct centrifugal force expression for the interior. The location of the centrifugal maxima gets further away from the Schwarzschild radius as the equation of state gets softer.