Detector software

The PANDA experiment at FAIR will study fundamental questions of strong
interaction with high precision. Efficient particle identification for a wide momentum
range and the full solid angle is required for successful reconstruction of the
benchmark channels of the broad PANDA physics program. For this purpose a compact
ring imaging Cherenkov detector is being developed for the barrel region of the
PANDA detector. The concept and the baseline design of the PANDA Barrel DIRC
were inspired by the BABAR DIRC and improved with important modifications,
like fast photon timing, a compact expansion volume, and focusing optics.
The required detector resolution was defined based on the PANDA PID specifications
using the phase space distributions of the final state kaons produced in
selected benchmark channels. To optimize the PANDA Barrel DIRC design in terms
of performance and cost the baseline detector geometry and a number of design options
were implemented in the simulation. The key options include the radiator
dimensions, two types of expansion volume shapes, and a variety of focusing systems.
The performance of the detector designs was quantified in terms of single
photon Cherenkov angle resolution and photon yield. It was found that the number
of radiators can be reduced by about 40% without loss in performance. A compound
spherical lens without air gap was found to be a promising focusing system. An optimized
Barrel DIRC design meeting the PID requirements includes three radiator
bars per flat section, the compound lens without air gap, a compact prism-shaped
EV, and a total of 192 Microchannel-Plate PMTs as photosensors. The number
of electronic channels can be halved without loss in performance by combining two
neighbouring pixels. For such a detector design the total cost will be significantly reduced
compared to the baseline version while still meeting or exceeding the PANDA
PID performance goals.

Hyperon production and the study of their properties is an important part of the physics programme of the future PANDA experiment at FAIR. Antihyperon-hyperon pairs will be produced in antiproton-proton collisions through the annihilation of at least one light antiquark-quark (u,d) pair and the creation of a corresponding number of antiquark-quark ss pairs. By measuring the decay products of the hyperons, spin observables such as the polarisation can be measured.
Many hyperons have a long life-time which give rise to final state particles originating from displaced vertices. A pattern recognition algorithm using information from the PANDA Straw Tube Tracker is extended to reconstruct not only the transversal, but also the longitudinal components of charged tracks. A Hough transform and a path finding method as tools to extract the longitudinal components is being developed.

The PANDA experiment in preparation to be setup at FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany will cover many important aspects of hadron physics with cooled anti-proton beams of unprecedented intensity and precision in the momentum range between 1.5 and 15 GeV/c.

The versatile detector is designed to address a rich physics program.
This includes spectroscopy of QCD bound states ranging from charmonium to states composed of light quarks only, which comprises studies of the recently and yet not understood X, Y, and Z states and searches for other exotics. Production of hyperons will shed further light on the
strong interaction in the intermediate region between the perturbative and non-perturbative regime. The time-like nuclear form factors and properties of hadrons in medium will be accessible and round up the experimental program.

In this talk aspects of the PANDA physics program will be highlighted. Major components of the detector are under construction. The current status of the experiment will be presented.

This note intends to give a status report on the activity performed together with genfit developers (from LMU and TUM, outside the Panda collaboration). genfit2 is the new (external package) tool providing a new implementation of Runge-Kutta track representation and the Kalman fitter. The genfit2 classes are here shortly documented, and hints on how to run genfit2 in PandaRoot are given. Examples of the good performance of genfit2 in PandaRoot are provided. The genfit2 official paper is in preparation; until the paper is not published, this note wants to provide some help, as a short manual for PANDA users.

Invitation talk - https://indico.hephy.oeaw.ac.at/event/86/ (22-24 Feb 2016, Vienna)

One of the physics highlights of the future PANDA experiment is to search for exotic states that have been predicted by theory, and whose properties are governed by the presence of valence gluons. Such exotic states can be formed directly and copiously in proton-antiproton annihilations. The challenge lies in reducing the enormous background yield while preserving a high efficiency for the detection of exotic hadrons. As the detector response of background events is very similar to that of the decay of the exotic states, the use of a conventional triggered readout scheme, where a limited number of subdetectors generates a trigger signal that engages the readout of the complete detector, is ruled out. Therefore, a new type of intelligent readout is being developed, where kinematic constraints are imposed online on reconstructed events. The high 20 MHz interaction rate can lead to overlapping detector response signals, creating so-called pile-up signals. Therefore, a different simulation approach is required, where events are no longer simulated sequentially, but are allowed to produce pile-up signals by letting simulated response signals interact with other signals in the same detector element for a set period of time. This means that the timestamp of each event (or even each hit produced by an event) plays a key role in the process, which is why this type of simulation is referred to as “timebased”. Disentangling these overlapping signals and assigning them to the proper events may prove difficult. For the Electromagnetic Calorimeter, impinging particles create groups of hits in the detector, called clusters. To find the energy of these particles, the information from the hits in each cluster has to be recombined. Ideally, each hit in a cluster should belong to the event that spawned it, but this depends on the efficiency of the disentangling procedure. Some results of tests of the timebased simulation code and a macro for disentangling and recombining hits into clusters will be presented.

This note presents the current status of the PANDA software trigger project. Apart from the
present results obtained from Monte Carlo simulated events for various PANDA physics channels
of interest, the task is defined and intersections to the DAQ and detector projects are pointed out.

The PANDA experiment will be build at the antiproton storage ring HESR, a part of the new accelerator facility FAIR in Darmstadt, Germany. PANDA aims amongst others for high precision measurements in hadron spectroscopy and search for exotic matter.
To guarantee the high resolution of the different components a detector control system (DCS) monitoring temperatures, humidity, pressure, and controlling chillers and power supplies is needed.
The DCS of PANDA is build using the open-source software package EPICS (Experimental Physics and Industrial Control System) with a PANDA specific version of Control-System Studio.
The concepts and plans for the PANDA DCS and new developments will be presented.

Proceedings for the talk at the DSPIN-15 workshop.

The corresponding release note can be found here:
https://panda.gsi.de/publication/rn-hyp-2015-009

And the talk here:
https://panda.gsi.de/publication/ta-con-2015-053

Submission deadline for the proceedings is October 15th with a maximum of 8 pages.