Reconstruction of electrons with the Gaussian sum filter in the CMS tracker at LHC

The bremsstrahlung energy loss distribution of electrons propagating in matter is highly non Gaussian. Because the Kalman filter relies solely on Gaussian probability density functions, it might not be an optimal reconstruction algorithm for electron tracks. A Gaussian-sum filter (GSF) algorithm for electron track reconstruction in the CMS tracker has therefore been developed. The basic idea is to model the bremsstrahlung energy loss distribution by a Gaussian mixture rather than a single Gaussian. It is shown that the GSF is able to improve the momentum resolution of electrons compared to the standard Kalman filter. The momentum resolution and the quality of the estimated error are studied with various types of mixture models of the energy loss distribution.

Note:

Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, LaTeX, 14 eps figures. PSN TULT009

talk: La Jolla 2003/03/24
electron: track data analysis
semiconductor detector: tracks
bremsstrahlung
tracks: energy loss
momentum resolution
CMS
CERN LHC Coll

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