An Object-Oriented Approach to Vertex Fitting

Paper: 397
Session: A (poster)
Presenter: Stamfest, Peter, Institute of High Energy Physics, Vienna
Keywords: algorithms, analysis, application programming, C++, object-oriented methods

An Object-Oriented Approach to Vertex Fitting

Winfried Mitaroff and Peter Stamfest

Institute of High Energy Physics of the Austrian Academy of Sciences
Nikolsdorfer Gasse 18, A-1050 Vienna, Austria

The analysis of data from a high-energy collider like LEP, HERA, BaBar or LHC
requires sophisticated statistical methods in order to exploit the precision of
modern complex detectors. The high spatial resolution of semiconductor vertex
detectors has made it possible to identify and fit secondary vertices and their
associated tracks from decays as short-lived as b hadrons.

For this task, a package has been developed by one author (W.M.) for the DELPHI
detector at LEP, based on the robust "M-estimator". Its superiority over con-
ventional estimation methods (least squares resp. Kalman filter) has been shown
with simulated and real data in an earlier study [1].

The package, originally written in Fortran-77, is presently being recoded by
one author (P.S.) in C++ using the CLHEP class library, with the aim of a
general-purpose detector-independent tool for an OO environment like the one
defined by the emerging LHC++ standards.

[1] Fruhwirth, Kubinec, Mitaroff, Regler: Comp.Phys.Comm. 96 (1996) 189.