Top Background to SM Higgs Searches in the W^{+}W^{-} \to l\nul\overline{\nu} Decay Mode at CMS

The top quark and its properties within and beyond the Standard Model will be extensively studied at the incoming Large Hadron Collider. Nonetheless the top quark will play the role of the main background for most of the Higgs and new physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs discovery channel will be studied. The current status of the Monte Carlo tools for t-tbar and single top simulation will be presented. Finally the problem on how to evaluate the top background from the data will be addressed and the related systematics will be discussed.The top quark and its properties within and beyond the Standard Model will be extensively studied at the incoming Large Hadron Collider. Nonetheless the top quark will play the role of the main background for most of the Higgs and new physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs discovery channel will be studied. The current status of the Monte Carlo tools for t-tbar and single top simulation will be presented. Finally the problem on how to evaluate the top background from the data will be addressed and the related systematics will be discussed

First measurements of inclusive W and Z cross sections from Run II of the Fermilab Tevatron collider

We report the first measurements of inclusive W and Z cross sections times leptonic branching ratios for pp¯ collisions at s√=1.96  TeV, based on their decays to electrons and muons. The data correspond to an integrated luminosity of 72  pb−1 recorded with the CDF detector at the Fermilab Tevatron. We test e-μ universality in W decays, and we measure the ratio of leptonic W and Z rates from which the leptonic branching fraction B(W→ℓν) can be extracted as well as an indirect value for the total width of the W and the Cabibbo-Kobayashi-Maskawa matrix element V c

Alignment of the CMS silicon strip tracker during stand-alone commissioning

The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.Comment: 41 pages, 63 postscript figures, submitted to JINS