A high-resolution pixel silicon Vertex Detector for open charm measurements with the \NASixtyOne spectrometer at the CERN SPS

TL;DR

This paper describes the design, implementation, and testing of a high-resolution pixel silicon Vertex Detector for open charm measurements in nucleus-nucleus collisions at the CERN SPS, enhancing the understanding of charm production in hot dense matter.

Contribution

It introduces a new vertex detector specifically designed for open charm detection in heavy-ion collisions, with detailed calibration and analysis methods.

Findings

Successful installation and operation during Pb+Pb and Xe+La collisions

High-resolution vertex reconstruction achieved

Enhanced capability for open charm measurement in heavy-ion experiments

Abstract

The study of open charm meson production provides an efficient tool for the investigation of the properties of hot and dense matter formed in nucleus-nucleus collisions. The interpretation of the existing di-muon data from the CERN SPS suffers from a lack of knowledge on the mechanism and properties of the open charm particle production. Due to this, the heavy-ion programme of the \NASixtyOne experiment at the CERN SPS has been extended by precise measurements of charm hadrons with short lifetimes. A new Vertex Detector for measurements of the rare processes of open charm production in nucleus-nucleus collisions was designed to meet the challenges of track registration and high resolution in primary and secondary vertex reconstruction. A small-acceptance version of the vertex detector was installed in 2016 and tested with Pb+Pb collisions at 150\AGeVc. It was also operating during the physics data taking on Xe+La and Pb+Pb collisions at 150\AGeVc conducted in 2017 and 2018. This paper presents the detector design and construction, data calibration, event reconstruction, and analysis procedure.