Precision measurement of the structure of the CMS inner tracking system using nuclear interactions

TL;DR

This paper presents a precise measurement of the CMS inner tracking system's structure using nuclear interactions from proton-proton collision data at 13 TeV, aiding in detector calibration and upgrades.

Contribution

It introduces a method to accurately determine the positions of CMS inner detector components using nuclear interactions, enhancing detector modeling and maintenance.

Findings

Precise positions of the beam pipe and detector elements were measured.

The method improves detector simulation accuracy.

Results assist in detector upgrades and stability assessments.

Abstract

The structure of the CMS inner tracking system has been studied using nuclear interactions of hadrons striking its material. Data from proton-proton collisions at a center-of-mass energy of 13 TeV recorded in 2015 at the LHC are used to reconstruct millions of secondary vertices from these nuclear interactions. Precise positions of the beam pipe and the inner tracking system elements, such as the pixel detector support tube, and barrel pixel detector inner shield and support rails, are determined using these vertices. These measurements are important for detector simulations, detector upgrades, and to identify any changes in the positions of inactive elements.