Track reconstruction with a central two-shell scintillating fibre tracker (SFT)

Abstract

We present a track reconstruction algorithm designed for the scintillating fibre tracker (SFT), having in view the upgrade of the L3 detector for LEP-II. This algorithm can also be applied for particle tracking at future hadron colliders. The tracking elements are polystyrene fibres of 60 μm diameter, which are arranged as fused coherent bundles into fibre layers. We study in particular a tracking setup, which consists of two concentric cylindrical shells each of 8 mm thickness, placed at r = 18.7 cm and r = 31.4 cm radius from the collider axis. The tracking reconstruction algorithm was tested with Monte Carlo generated e + e − events at 185 GeV c.m. energy and comparing them with the reconstructed events. It achieves for particle momenta above 0.2 GeV/ c a track reconstruction efficiency of nearly 100% for primary charged tracks with less than 1% contribution of ghost tracks. The average error on the reconstructed momenta for single tracks is around 3% and the average error on the reconstructed total momentum per event is around 6%.