Detector software

The PANDA experiment (antiProton ANnihilation at DArmstadt) is one of the four key experiments to be operated at FAIR (Facility for Antiproton and Ion Research), which is currently under construction near Darmstadt/Germany. This fixed target experiment will address a wide range of open questions in the field of hadron physics.
The detector consists of at target as well as a forward spectrometer to fully exploit the forward boosted collisions of antiprotons with dense hydrogen or nuclear targets.
Phase-space cooled antiprotons with momenta in the range of 1.5 GeV/c to 15 GeV/c provided by the High Energy Storage Ring (HESR) allow for high precision line-shape scans.
The ability to perform exclusive reconstruction of arbitrary final states enables a physics program including topics such as spectroscopy in the charmonium and open-charm region, proton structure, and hyperon and hypernuclear physics.
The talk will give an overview of the PANDA experiment and highlight the most important aspects of the physics program.

PANDA Annual Report 2019

PANDA Collaboration Meeting 20/1 Minutes

The P̄ANDA experiment represents the central part of the hadron physics program at the
FAIR facility that is under construction at GSI in Darmstadt. In the early stages of the
experiment, during the commissioning phase, a proton beam instead of an antiproton
beam will be provided by the accelerator and the reduced Day-1 setup will be available.
One of the first experiments that could be performed already during the commissioning
phase are cross section measurements of π 0 and η production in proton proton reactions.
The reconstruction efficiency for photons, π⁰, η and protons of the Day-1 setup has
been studied using PandaRoot simulations. In addition the full meson production chain
including baryonic resonances has been simulated and efficiencies for complete final
state reconstruction have been determined. There are some losses due to the incomplete
Day-1 setup but the relevant phase space for those reactions is covered sufficiently well.
P̄ANDA will be able to contribute to the measurement of total as well as differential meson
production cross sections with high precision. Moreover a first study on the channel
p̄p → φφπ⁰ has been performed. P̄ANDA could play an important role in confirming the
existence of the predicted 2 ++ glueball resonance in φφ and measure its properties.

PANDA Management Quarterly Report 19Q4

The PANDA experiment at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR) near GSI, Darmstadt, Germany will address fundamental questions of hadron physics. Excellent particle identification is required to achieve the PANDA physics goals. Hadronic particle identification (PID) in the PANDA target spectrometer will be delivered by two DIRC (Detection of Internally Reflected Cherenkov light) counters. The Barrel DIRC will cover the polar angle range of 22−140 degree and is designed to provide pion/kaon separation for momenta between 0.5 GeV/c and 3.5 GeV/c with a separation power of at least 3 standard deviations. Several reconstruction algorithms have been developed to determine the performance of the detector. The "geometrical reconstruction" determines the Cherenkov angle relying primarily on the position of the detected photons. The "time imaging", however, utilizes both position and time measurements by directly performing the maximum likelihood fit. GEANT4 simulations and experimental data from prototype tests at the CERN PS were used to optimize the performance of the algorithms. We will discuss detailed aspects of both reconstruction approaches.

High event rates of up to 20 MHz and continuous detector readout makes the event filtering at PANDA a challenging task. In addition, no hardware-based event selection will be possible due to the similarities between signal and background. This makes PANDA among a new generation of experiments utilizing a fully software-based event filtering. Classically, detector hits are pre-sorted into events by the hardware filter before being passed to the software-based event filter with track reconstruction and event building. Track reconstruction will play a key part in the online filtering at PANDA where it will be used iteratively together with the event building.

To ensure the quality of the track reconstruction, the existing quality assurance task has been modified to be able to cope with free streaming data. This talk will address the data stream at PANDA as well as the candidates for online track reconstruction algorithms for free streaming data based e.g. on the Cellular Automaton. The quality assurance procedure and the results from the tracking at different event rates and level of event mixing is presented.

The PANDA experiment of the FAIR facility will address open
questions in hadron physics using antiproton beams in the
momentum range of 1.5-15 GeV/c.
The antiprotons are stored and cooled in the High Energy
Storage Ring (HESR) and allow high precision spectroscopy in
the energy range of closed and open charm.
Two Cherenkov detectors using the principle of Detection of
Internally Reflected Cherenkov light (DIRC) will provide
excellent PID in the PANDA target spectrometer.
The Endcap Disc DIRC separates pions from kaons better than
3σ up to momenta of 4 GeV/c in the forward direction, for polar
angles from 5∘ to 22∘.
It uses a fused silica radiator disk, consisting of four
optically isolated quadrants.
The Cherenkov photons are imaged on Microchannel-Plate PMTs
(MCP-PMTs) by focusing lightguides.
The Barrel DIRC cleanly separates pions from kaons for polar
angles in the range of 22∘ - 140∘ and momenta up to 3.5 GeV/c.
The barrel is formed by 16 sectors, each comprising three narrow
fused silica radiator bars, with a flat mirror attached to
one end and a spherical lens attached to the other, and a
large fuse silica prism, coupled to each group of three lenses.
The Cherenkov light is focused on the back side of the prism,
where an array of lifetime-enhanced MCP-PMTs detects the photons.

The designs are simulated and validated in test beams with
prototypes and the Technical Design Reports of both devices
have recently been completed.
While mass production of some of the components has already
started, the R&D for other important items, like the readout
electronics or the shape and materials of the mechanical support,
is still ongoing.
This talk describes the status of the two DIRC projects and will
discuss the remaining R&D activities.

PANDA Collaboration Meeting 19/3 Minutes

Overview and Status of FAIR. Shows three Panda slides on Detector and Physics Program.