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The (anti-Proton ANnihiliation at DArmstadt) experiment will be one of the four flagship experiments at the new international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. will address fundamental questions of hadron physics and quantum chromodynamics using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c and a design luminosity of up to 2 × 1032 cm−2 s−1. Excellent particle identification (PID) is crucial to the success of the physics program. Hadronic PID in the barrel region of the target spectrometer will be performed by a fast and compact Cherenkov counter using the detection of internally reflected Cherenkov light (DIRC) technology. It is designed to cover the polar angle range from 22° to 140° and will provide at least 3 standard deviations (s.d.) π/K separation up to 3.5 GeV/c, matching the expected upper limit of the final state kaon momentum distribution from simulation. This documents describes the technical design and the expected performance of the Barrel DIRC detector. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean π/K separation with at least 3 s.d. over the entire phase space of charged kaons in the Barrel DIRC.

The exclusive charmonium production process inpp annihilation with an associated π 0 mesonpp → J=ψπ 0 is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J=ψ → e þ e − decay channel with the AntiProton ANnihilation at DArmstadt (PANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including thepp → π þ π − π 0 andpp → J=ψπ 0 π 0 reactions are performed with PANDAROOT, the simulation and analysis software framework of thePANDA experiment. It is shown that the measurement can be done atPANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.

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New precision measurement of the J/ψ -and ψ The relative measurement accuracy has reached 4 · 10 −6 for J/ψ and 7 · 10 −6 for ψ ′ , approximately 3 times better than in the previous precise experiments.

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The e + e − → KSKLπ 0 cross section is measured in the center-of-mass energy range √ s = 1.3−2.0 GeV. The analysis is based on the data sample with an integrated luminosity of 33.5 pb −1 collected with the SND detector at the VEPP-2000 e + e − collider.