ATLAS

Abstract:

A measurement of the calorimeter response to isolated charged hadrons in the ATLAS detector at the LHC is presented. This measurement is performed with 3.2 nb[Formula: see text] of proton-proton collision data at [Formula: see text] [Formula: see text] from 2010 and 0.1 nb[Formula: see text] of data at [Formula: see text] [Formula: see text] from 2012. A number of aspects of the calorimeter response to isolated hadrons are explored. After accounting for energy deposited by neutral particles, there is a 5% discrepancy in the modelling, using various sets of Geant4 hadronic physics models, of the calorimeter response to isolated charged hadrons in the central calorimeter region. The description of the response to anti-protons at low momenta is found to be improved with respect to previous analyses. The electromagnetic and hadronic calorimeters are also examined separately, and the detector simulation is found to describe the response in the hadronic calorimeter well. The jet energy scale uncertainty and correlations in scale between jets of different momenta and pseudorapidity are derived based on these studies. The uncertainty is 2-5% for jets with transverse momenta above 2 [Formula: see text], where this method provides the jet energy scale uncertainty for ATLAS.

Abstract:

Requirements of HEP experiments lead to highly integrated systems with many electrical, mechanical and thermal constraints. A complex performance optimisation is therefore required. High-speed data transmission lines are designed using copper-polyimide flexible bus tapes rather than cable harnesses to minimise radiation length. Methods to improve the signal integrity of point-to-point links and multi-drop configurations in an ultra-low-mass system are described. FEA calculations are an essential guide to the optimisation of a tape design which supports data rates of 640 Mbps for point-to-point links over a length of up to 1.4 m, as well as 160 Mbps for multi-drop configuration. The designs were validated using laboratory measurements of S-parameters and direct bit error ratio tests.

Abstract:

The Fermilab Tevatron produced proton-antiproton collisions at a center-of-mass energy of vs = 1.96 TeV between 2001 and 2011. Using an integrated luminosity of ˜ 10 fb-1 collected by each of the two general-purpose experiments CDF and D0, many high-precision measurements were performed. I summarize the three electroweak measurements with the highest precision: the W-boson mass, the top-quark mass, and the effective Z-boson vector couplings.