On-line reconstruction algorithms for the CBM and ALICE experiments

This thesis presents various algorithms which have been developed for on-line event reconstruction in the CBM experiment at GSI, Darmstadt and the ALICE experiment at CERN, Geneve. Despite the fact that the experiments are different — CBM is a fixed target experiment with forward geometry, while ALICE has a typical collider geometry — they share common aspects when reconstruction is concerned. The thesis describes: — general modifications to the Kalman filter method, which allows one to accelerate, to improve, and to simplify existing fit algorithms; — developed algorithms for track fit in CBM and ALICE experiment, including a new method for track extrapolation in non-homogeneous magnetic field. — developed algorithms for primary and secondary vertex fit in the both experiments. In particular, a new method of reconstruction of decayed particles is presented. — developed parallel algorithm for the on-line tracking in the CBM experiment. — developed parallel algorithm for the on-line tracking in High Level Trigger of the ALICE experiment. — the realisation of the track finders on modern hardware, such as SIMD CPU registers and GPU accelerators. All the presented methods have been developed by or with the direct participation of the author.