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Status of ranger

ranger/ideal is able to do a full track fit from the vertex detector to the begin of the ECAL. Multiple scattering and - in case of electrons - radiation inside the magnet are taken into account. The magnetic field variant - homogeneous or inhomogeneous - is recognized automatically. The multiple scattering correction suffers a little from the incompleteness of the geometry description inside Arte. ranger/ideal has been successfully used for a couple of MC analysis works, eg. by Jenny Ivarsson (Lund Univ.) and Matthias Leuthold (Humboldt Univ. Berlin), with subsequent vertex fitting.

ranger/triplet was introduced in ranger 4.6. Extensive performance studies have shown that pattern recognition efficiencies better than 96% are obtained for particles from the tex2html_wrap_inline137 decay with the standard HERA-B simulation (1 tex2html_wrap_inline139 interaction plus 4 inelastic interactions (on average)) [2].

ranger/magnet was introduced in ranger 4.7. This is still a very preliminary implementation. It is quite slow because a lot of time is spent in the Runge-Kutta transport, which has to be fitted more elaborately to our needs. There is currently no final refit of the magnet tracks, so that the track parameters should be regarded as preliminary.

ranger/fit will be relevant when the track segments from vertex detector and main tracker have successfully been merged.



Rainer Mankel
Wed Feb 12 13:34:24 MET 1997