A Global Event Description using Particle Flow with the CMS Detector
  The CMS Detector consists of a large volume silicon tracker immersed in a high four Tesla magnetic field, together with a high resolution/granularity electromagnetic calorimeter and a nearly full solid angle coverage hadronic calorimeter. Particle flow reconstruction provides a global pp-collision event description by exploiting the combined information across all CMS sub-detectors, optimizing the reconstruction and the identification of each particle (photons, electrons, muons, unstable neutral hadrons, charged hadrons and neutral hadrons) in an event. This summary introduces the CMS particle flow algorithm, discusses the challenges associated with the LHC environment, and presents some first example results in the context of hadronic decays of taus as well as missing transverse energy. 
Joanna Weng