A parametrized Kalman filter for fast track fitting at LHCb

TL;DR

This paper introduces a parametrized Kalman filter for LHCb track fitting that significantly speeds up processing while preserving accuracy, suitable for real-time trigger systems in particle physics experiments.

Contribution

It presents a novel, simplified Kalman filter implementation with parametrized extrapolation and scattering effects, enabling faster track fitting at LHCb.

Findings

Over fourfold speed increase in track fitting

Maintains high quality of track estimates

Suitable for real-time trigger systems

Abstract

We present an alternative implementation of the Kalman filter employed for track fitting within the LHCb experiment. It uses simple parametrizations for the extrapolation of particle trajectories in the field of the LHCb dipole magnet and for the effects of multiple scattering in the detector material. A speedup of more than a factor of four is achieved while maintaining the quality of the estimated track quantities. This Kalman filter implementation could be used in the purely software-based trigger of the LHCb upgrade.