Proton reconstruction with the TOTEM Roman pot detectors for high-$\beta^*$ LHC data

TL;DR

This paper introduces advanced proton track reconstruction and detector alignment techniques for the TOTEM Roman pot detectors, enhancing the precision of proton measurements in high-$eta^*$ LHC data-taking at 13 TeV.

Contribution

It presents novel methods for track reconstruction, detector alignment, and efficiency measurement, improving the accuracy of proton detection in high-energy collider experiments.

Findings

Achieved 3 μm horizontal and 60 μm vertical alignment precision.

Developed a new track reconstruction method using a polygonal area in intercept-slope plane.

Validated detector efficiencies and beam optics through cross-checks.

Abstract

The TOTEM Roman pot detectors are used to reconstruct the transverse momentum of scattered protons and to estimate the transverse location of the primary interaction. This paper presents new methods of track reconstruction, measurements of strip-level detection efficiencies, cross-checks of the LHC beam optics, and detector alignment techniques, along with their application in the selection of signal collision events. The track reconstruction is performed by exploiting hit cluster information through a novel method using a common polygonal area in the intercept-slope plane. The technique is applied in the relative alignment of detector layers with $\mu$m precision. A tag-and-probe method is used to extract strip-level detection efficiencies. The alignment of the Roman pot system is performed through time-dependent adjustments, resulting in a position accuracy of 3 $\mu$m in the horizontal and 60 $\mu$m in the vertical directions. The goal is to provide an optimal reconstruction tool for central exclusive physics analyses based on the high-$\beta^*$ data-taking period at $\sqrt{s}$ = 13 TeV in 2018.