PANDA is a future hadron and nuclear physics experiment at the FAIR facility in construction in Darmstadt, Germany. In contrast with the majority of current experiments, PANDA's strategy for data acquisition is based on event reconstruction and selection from free-streaming data, performed in real time entirely by software algorithms using global detector information.
This paper reports the status of the development of algorithms for the reconstruction of charged particle tracks, optimized for use in online data processing applications, using General-Purpose Graphic Processing Units.
Two algorithms for trackfinding, the Triplet Finder and the Circle Hough are described, with details of their GPU implementations. Average track reconstruction times of less than 100 ns are obtained running the Triplet Finder on state-of-the-art computing-grade GPU cards.
In addition, a proof-of-concept system for the dispatch of data to tracking algorithms using Message Queues is presented.
Submitted by e.atomssa on Wed, 08/04/2015 - 11:01.
The study of nucleon structure is one of the main physics goals of PANDA to be built at the FAIR accelerator complex. The excellent particle identification performance of the PANDA detector will enable measurements of exclusive channels p̄ p → e+e− and p̄ p → π0 J/ψ → π0e+e− to extract the electromagnetic form factors of protons and π-nucleon Transition Distribution Amplitudes (π-N TDAs). After a brief description of the PANDA apparatus and a method to handle momentum resolution degradation due to Bremsstrahlung, the physics of π-N TDAs is discussed. An estimate for the expected signal to background ratio for p̄ p → π0 J/ψ → π0e+e− that takes into account the main background source is given.
Submitted by e.prencipe on Thu, 19/03/2015 - 11:54.
The sector of Charm and Charmonium physics is richer than expected respect to the potential model predictions, as new resonant states with quite unusual properties have been observed. Prominent examples are the $X(3872)$ and the charged $Z_c^+(3900)$ in the Charmonium sector, and the $D_s$ mesons below the $DK$ threshold in the Charm sector. $Strangeness$ seems a topic still to be exploited, in both Charm and Charmonium field. For example, the number of publications in the past 5 years in searching for hybrids in the invariant mass distribution of $J/ \psi K K$, in B decays and via 2-photon interactions, gives an idea of the renewed interest in this field, from theoretical and experimental point of view. However, composite systems of heavy-light quarks have gained the attention of the Charm-community since the discovery of the Ds0*(2317)+, that was unexpected found more than 100 MeV below the potential model predictions. As consequence, several theoretical interpretations have been proposed for these resonant states like hadro-charmonia, hybrids, tetraquarks and hadronic molecules. High quality calculations as well as measurements are compulsory for each state to allow one to decide amongst the various scenarios. The measurement of the width of narrow states is essential to discriminate among different theoretical approaches. We present a method to determinate the width of the Ds*(2317)+ at the experiment PANDA, together with the status of our simulations and future perspectives, in relation with the recent measurements performed by LHCb and the performance obtained in this field at the B factories.
The future PANDA-Experiment at the FAIR accelerator facility in Darmstadt/Germany utilizes an antiproton beam with momenta of 1.5 - 15 GeV/\boldmath$c$\unboldmath~incident on a hydrogen or heavy element fixed target. It addresses open questions concerning the strong interaction with one focus on high precision charmonium spectroscopy. The spatial and timing resolution in detecting fast-decaying particles e.g. in open-charm channels is crucial and requires the application of thin solid state detectors coupled with a fast untriggered readout electronics. The contribution will focus on the silicon microstrip tracker of the innermost subdetector, the Micro Vertex Detector (MVD), which is composed of double-sided silicon strip detectors (DSSDs). These are connected to ultra-thin flex modules carrying novel fast self-triggering front-end ASICs named PASTA. The construction of the DSSD modules, the carrier PCB and the architecture of the PASTA chip will be discussed as well as methods to qualify the sensors. An overview of the
prototypes developed and tested up to now is given together with the future steps to be taken in order to arrive at the mass production of the full-scale modules.