Talk

The new Facility for Antiproton and Ion Research (FAIR) is currently
being built at GSI in Darmstadt (Germany), where the PANDA experiment
represents the central part of the hadron physics programme. The field
of hadron spectroscopy has gained new momentum by the discovery of
various new hadronic resonances especially in the charmonium sector over
the past two decades. The nature of many of the so-called
charmonium-like exotic XYZ states are, however, not yet understood.
Precise measurements of hadron properties are mandatory to sort out
different theoretical models and clarify the nature of these new states.
A well known example is the X(3872) (now χc1(3872)) ---
although being the first of the new charmonium-like states discovered
since 2003, the nature of this state is still not understood.

The most important ingredients to address this issue are measurements of
the mass, natural width and in particular the shape of the
χc1(3872). While a high statistic analysis (the most precise one
up to now) recently published by LHCb demonstrated very limited power to
identify the nature, it will be shown, that high-precision energy scan
experiments carried out with pbar-p annihilation at PANDA will have
a high impact on resolving the current ambiguities.

Excellent particle identification (PID) will be essential for the PANDA experiment at FAIR. The Barrel DIRC will separate kaons and pions with at least 3 s.d. for momenta up to 3.5 GeV/c and polar angles between 22 and 140 deg.
After the successful validation of the final design in the CERN PS/T9 beam line, the tendering process for the two most time- and cost-intensive items, radiator bars and MCP-PMTs, started in 2018. In Sep. 2019 Nikon was selected to build the fused silica bars and successfully completed the series production of 112 bar in Feb. 2021. Measurements of the mechanical quality of the bars were performed by Nikon and the optical quality was evaluated at GSI. In Dec. 2020, the contract for the fabrication of the MCP-PMTs was awarded to PHOTONIS and the delivery of the first-of-series MCP-PMTs is expected in June 2021.
We present the design of the PANDA Barrel DIRC as well as the status of the component series production and the result of the quality assurance measurements.

PANDA (antiProton ANnihilation in DArmstadt) is the central experiment to fully exploit the physics research potential of antiproton beams at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR), currently under construction at GSI. Phase-space cooled high intensity antiproton beams up to 15 GeV/c will be provided by the High Energy Storage Ring (HESR) at FAIR to interact with PANDA internal proton or nuclear targets enabling a broad range of exciting studies in Particle and Nuclear Physics. The PANDA detector features two spectrometers, the Target Spectrometer with a superconducting solenoid magnet of 2 T around the interaction region with hermetic coverage and the Forward Spectrometer with a 2 Tm dipole magnet for coverage of the forward boosted particles. Several modern particle detector systems are employed in PANDA to provide excellent charged particle tracking, particle identification, calorimetry and muon detection, over the full momentum range in both spectrometers throughout the lifetime of the experiment. Focusing on the various PANDA detector systems we present an overview of recent developments, the detector construction progress and conclude with an outline for a phased deployment of PANDA at FAIR.