Open charm measurements in NA61/SHINE at CERN SPS

TL;DR

This paper discusses the first direct measurements of open charm meson production in heavy ion collisions at SPS energies using the NA61/SHINE experiment with a new Vertex Detector, providing insights into hot dense matter properties.

Contribution

It introduces the implementation of a Vertex Detector in NA61/SHINE for direct open charm measurements and presents initial test results validating the detection method.

Findings

First indication of open charm production in Pb+Pb collisions at SPS energies.

Validation of D0 meson detection via its decay channel.

Future plans for comprehensive open charm measurements.

Abstract

The measurements of open charm production was proposed as an important tool to investigate the properties of hot and dense matter formed in nucleus-nucleus collisions as well as to provide the means for model independent interpretation of the existing data on $\text{J}/\psi$ suppression. Recently, the experimental setup of the NA61/SHINE experiment was supplemented with a Vertex Detector which was motivated by the importance and the possibility of the first direct measurements of open charm meson production in heavy ion collisions at SPS energies. First test data taken in December 2016 on Pb+Pb collisions at 150$A$ GeV/$c$ allowed to validate the general concept of D$^0$ meson detection via its D$^0 \to \pi^+ + K^-$ decay channel and delivered a first indication of open charm production. The physics motivation of open charm measurements at SPS energies, pilot results on open charm production, and finally, the future plans of open charm measurements in the NA61/SHINE experiment after LS2 are presented.