Efficiency of Si-strips sensors used in Precision Proton Spectrometer

The Precision Proton Spectrometer (PPS) is a forward-proton spectrometer using near-beam detectors (Roman Pots, RPs) located symmetrically on both sides of IP5 at a distance of about 220 m. At The early stage of the project, the tracking RPs were equipped with Si-strip sensors used in the TOTEM experiment. Having been conceived for low luminosity and low pileup conditions, these detectors cannot resolve multiple tracks and have low radiation hardness. These constitute the two major sources of inefficiency in high luminosity and high pileup runs. This note describes the method and results of evaluating the Si-strip inefficiency due to multiple tracks.