CMS Tracking Performance Results from early LHC Operation

TL;DR

This paper reports on the initial performance of the CMS detector's tracking system during early LHC proton-proton collisions at 0.9 and 2.36 TeV, demonstrating its capabilities in track reconstruction and detector calibration.

Contribution

It presents the first performance results of the CMS silicon tracker during early LHC operation, including calibration, efficiency, and resolution benchmarks.

Findings

High tracking efficiency achieved

Good resolution in track and vertex reconstruction

Effective identification of particle decays and interactions

Abstract

The first LHC pp collisions at centre-of-mass energies of 0.9 and 2.36 TeV were recorded by the CMS detector in December 2009. The trajectories of charged particles produced in the collisions were reconstructed using the all-silicon Tracker and their momenta were measured in the 3.8 T axial magnetic field. Results from the Tracker commissioning are presented including studies of timing, efficiency, signal-to-noise, resolution, and ionization energy. Reconstructed tracks are used to benchmark the performance in terms of track and vertex resolutions, reconstruction of decays, estimation of ionization energy loss, as well as identification of photon conversions, nuclear interactions, and heavy-flavour decays.