Ranger - a Pattern Recognition Algorithm for the HERA-B Main Tracking System: Part IV: The Object-Or

A rigorous track tting procedure for the HERA-B spectrometer is presented. The method is capable of dealing with a variety of detector types. Corrections for multiple scattering, ionization energy loss and radiation of bremsstrahlung for e are incorporated. The interaction time can be determined for tracks passing drift chambers by introducing an additional parameter into the t. The algorithm has been implemented in C++ using object-oriented techniques. The performance of the method is tested using simulated tracks in the standard HERA-B software environment.