Status of CMS Commissioning

The status of the installation of the detectors for the CMS experiment and the global commissioning campaign by May 2008 are summarized

The Petrochemical Industrial Complex of the St. Charles Parish Industrial Corridor and its Influence on Urbanization Patterns

This thesis explores the impact that the petrochemical industry has had on the built environment of Norco, St. Charles Parish, Louisiana. Previous scholars have suggested that heavy industry in Norco consumes a majority of the Mississippi River\u27s natural levee, which is the most elevated and flood resistant land in the town. In order to test these observations, the author of this thesis has collected parcel-level land use data in Norco to determine the flood hazard and topographical characteristics of these various land uses. Spatial calculations, run using Geographic Information System software, have determined that heavy industrial land uses in Norco consume a vast majority of the Mississippi River\u27s natural levee

Measuring Muon Reconstruction Efficiency from Data

We suggest a method of measuring the global muon reconstruction efficiency epsilon directly from data, which largely alleviates uncertainties associated with our ability to monitor and reproduce in Monte Carlo simulation all details of the underlying detector performance. With the data corresponding to an integrated luminosity L = 10 fb^-1, the precision of measuring epsilon for muons in the P_T range of 10-100~GeV will be better than 1%

CMS Trigger Improvements Towards Run II

AbstractThe trigger systems of the LHC detectors play a crucial role in determining the physics capabilities of the experiments. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1), implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. Both systems need to provide an efficient and fast selection of events, to keep the average write-out rate below 1 kHz. For Run II, the doubling of both the center of mass energy to 13 TeV and the collision rate to 40 MHz, will imply increased cross sections and out-of-time pile-up. We will present the improvements brought to both L1 and HLT strategies to meet those new challenges

The Track-Finding Processor for the Level-1 Trigger of the CMS Endcap Muon System

We report on the development and test of a prototype track-finding processor for the level-1 trigger of the CMS endcap muon system. The processor links track segments identified in the cathode strip chambers of the endcap muon system into complete three-dimensional tracks, and measures the transverse momentum of the best track candidates from the sagitta induced by the magnetic bending. The algorithms are implemented using SRAM and Xilinx Virtex FPGAs, and the measured latency is 15 clocks. We also report on the design of the pre-production prototype, which achieves further latency and size reduction using state-of-the-art technology. (4 refs)

The Underlying Event at the LHC

We discuss a study of "minimum-bias'' collisions and the "Underlying Event" at CMS (under nominal conditions) by measuring charged particles and muons. The Underlying Event is studied by examining charged particles in the "transverse" region in charged particle jet production and in the central region of Drell-Yan muon-pair production (after removing the muon-pair)

Measurement of the azimuthal angle distribution of leptons from\u3ci\u3eW\u3c/i\u3e boson decays as a function of the \u3ci\u3eW\u3c/i\u3e transverse momentum in \u3ci\u3epp̅\u3c/i\u3e collisions at √s = 1.8 TeV

We present the first measurement of the A2 and A3 angular coefficients of the W boson produced in proton-antiproton collisions. We study W → e νe and W → e νe candidate events produced in association with at least one jet at CDF, during Run Ia and Run Ib of the Tevatron at √s =1:8 TeV. The corresponding integrated luminosity was 110 pb-1. The jet balances the transverse momentum of the W and introduces QCD effects in W boson production. The extraction of the angular coefficients is achieved through the direct measurement of the azimuthal angle of the charged lepton in the Collins-Soper rest-frame of the W boson. The angular coefficients are measured as a function of the transverse momentum of the W boson. The electron, muon, and combined results are in good agreement with the standard model prediction, up to order αs2 in QCD

Direct photon cross section with conversions at CDF

We present a measurement of the isolated direct photon cross section in pp̅ collisions at √s =1.8 TeV and |η|0→γγ and η→γγ events from the data we use a new background subtraction technique which takes advantage of the tracking information available in a photon conversion event. We find that the shape of the cross section as a function of photon pT is poorly described by next-to-leading-order QCD predictions, but agrees with previous CDF measurements

Search for scalar leptoquark pairs decaying to νν̅ qq̅ in \u3ci\u3epp̅\u3c/i\u3e collisions at √s=1.96 TeV

We report on a search for the pair production of scalar leptoquarks (LQ), using 191 pb-1 of proton-antiproton collision data recorded by the CDF experiment during Run II of the Tevatron. The leptoquarks are sought via their decay into a neutrino and quark yielding missing transverse energy and several jets of large transverse energy. No evidence for LQ production is observed, and limits are set on sigma(pp̅→LQ L̅Q̅X→ νν̅qq̅X). Using a next-to-leading order theoretical prediction of the cross section for LQ production, we exclude first-generation LQ in the mass interval 78 to 117 GeV/c2 at the 95% confidence level for BR(LQ→νq)=100%