Numerical complexity of helix unraveling algorithm for charged particle tracking

Abstract

This paper describes a procedure for a realistic estimation of the number of iterations in the main loop of a recent particle detection algorithm from [1]. The calculations are based on a Monte Carlo simulation of the ATLAS inner detector. The resulting estimates of numerical complexity suggest that using the procedure from [1] for online triggering is not feasible. There are however some areas, such as triggering for particles in a specific sub-domain of the phase space, where using this procedure might be beneficial.