Performance studies of the CMS strip tracker before installation

Peer reviewe

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

Improved measurement of B+->rho(+)rho(0) and determination of the quark-mixing phase angle alpha

We present improved measurements of the branching fraction B, the longitudinal polarization fraction f(L), and the direct CP asymmetry A(CP) in the B meson decay channel B+->rho(+)rho(0). The data sample was collected with the BABAR detector at SLAC. The results are B(B+->rho(+)rho(0))=(23.7 +/- 1.4 +/- 1.4)x10(-6), f(L)=0.950 +/- 0.015 +/- 0.006, and A(CP)=-0.054 +/- 0.055 +/- 0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the Cabibbo-Kobayashi-Maskawa phase angle alpha=arg(-VtdVtb*/VudVub*) to be (92.4(-6.5)(+6.0))degrees

Stand-alone cosmic muon reconstruction before installation of the CMS silicon strip tracker

The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15% of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses.Comment: Added missing LaTex command / no change in contents w.r.t. v

Track Reconstruction with Cosmic Ray Data at the Tracker Integration Facility

The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15\,\% of the final silicon strip detector, and over 4.7~million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses