Influence of the straw tube sagging on the SHiP Spectrometer Straw Tracker performance

Effect of straw tube sagging on the track reconstruction performance of the SHiP Spectrometer Straw Tracker is considered. For this study, the sagging of the tubes and wires has been implemented in FairShip, a software package developed for SHiP event simulation and reconstruction. Degradation of the track spatial and momentum resolution is observed, as expected. Two different cases are studied, which are same sagging applied to all straw tubes, and different randomly distributed offset applied. It is found that if the straw tubes have different sagging, the performance become worse significantly compared with equal sagging for all tracking straws.