One of the main goals of the HADES experiment is to achieve a detailed understanding of dielectron emission from hadronic systems at moderate bombarding energies. Results obtained on electron pair ...production in elementary
N+
N collisions pave the way to a better understanding of the origin of the pair excess seen in heavy-ion collisions. This puzzling excess, reported first by the former DLS experiment, is now being investigated systematically by HADES.
An ATCA-based computation platform for data acquisition and trigger (TDAQ) applications has been developed for multiple future projects such as PANDA, HADES, and BESIII. Each Compute Node (CN) ...appears as one of the fourteen Field Replaceable Units (FRU) in an ATCA shelf, which in total features a high performance of 1890 Gbps inter-FPGA onboard channels, 1456 Gbps inter-board backplane connections, 728 Gbps full-duplex optical links, 70 Gbps Ethernet, 140 GBytes DDR2 SDRAM, and all computing resources of 70 Xilinx Virtex-4 FX60 FPGAs. Corresponding to the system architecture, a hardware/software co-design approach is proposed to ease and accelerate the development for different experiments. In the uniform system design, application-specific computation is to be implemented as customized hardware co-processors, while the embedded PowerPC processor takes charge of flexible slow controls and transmission protocol processing.
Based on the ATCA computation architecture and compute nodes (CN), investigation and implementation work has been being executed for HADES and PANDA trigger algorithms. We present our designs for ...HADES track reconstruction processing, Cherenkov ring recognition, time-of-flight processing, electromagnetic shower recognition, and the PANDA straw tube tracking algorithm. They will appear as co-processors in the uniform system design to undertake the detector-specific computing. The algorithm principles was explained and hardware designs was described in the paper. The current progress reveals the feasibility to implement these algorithms on FPGAs. Also experimental results demonstrate the performance speedup when compared to alternative software solutions, as well as the potential capability of high-speed parallel/pipelined processing in data acquisition and trigger systems.
First results of the differential cross section in dp elastic scattering at 1.25 GeV/u measured with the HADES over a large angular range are reported. The obtained data corresponds to large ...transverse momenta, where a high sensitivity to the two-nucleon and three-nucleon short-range correlations is expected.
The preliminary results on charged pion production in np collisions at an incident beam energy of 1.25 GeV measured with HADES are presented. The np reactions were isolated in dp collisions at 1.25 ...GeV/u using the Forward Wall hodoscope, which allowed to register spectator protons. The results for np -> pppi-, np -> nppi+pi- and np -> dpi+pi- channels are compared with OPE calculations. A reasonable agreement between experimental results and the predictions of the OPE+OBE model is observed.
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