# The Barrel DIRC detector of PANDA

## TL;DR

The paper presents the design, implementation, and test results of the Barrel DIRC detector for the PANDA experiment, which provides particle identification capabilities crucial for high-precision QCD studies at FAIR.

## Contribution

It introduces the novel Barrel DIRC detector design and demonstrates its performance through test beam results, highlighting its particle separation capabilities.

## Key findings

- Achieves pion-kaon separation of 3 standard deviations up to 3.5 GeV/c
- Test beam results validate the detector's photon detection efficiency
- Demonstrates effective particle identification in a compact design

## Abstract

The PANDA experiment is one of the four large experiments being built at FAIR in Darmstadt. It will use a cooled antiproton beam on a fixed target within the momentum range of 1.5 to 15 GeV/c to address questions of strong QCD, where the coupling constant $\alpha_s \gtrsim 0.3$. The luminosity of up to $2 \cdot 10^{32} cm^{-2}s^{-1}$ and the momentum resolution of the antiproton beam down to \mbox{$\Delta$p/p = 4$\cdot10^{-5}$} allows for high precision spectroscopy, especially for rare reaction processes. Above the production threshold for open charm mesons the production of kaons plays an important role for identifying the reaction. The DIRC principle allows for a compact particle identification for charged particles in a hermetic detector, limited in size by the electromagnetic lead tungstate calorimeter. The Barrel DIRC in the target spectrometer covers polar angles between $22^\circ$ and $140^\circ$ and will achieve a pion-kaon separation of 3 standard deviations up to 3.5 GeV/$c$. Here, results of a test beam are shown for a single radiator bar coupled to a prism with $33^\circ$ opening angle, both made from synthetic fused silica read out with a photon detector array with 768 pixels.