Presentation on theme: "PANDA Ulrich Wiedner, FAIR PAC meeting, March 14, 2005."— Presentation transcript:
PANDA Ulrich Wiedner, FAIR PAC meeting, March 14, 2005.
PANDA Collaboration At present a group of 340 physicists from 46 institutions of 14 countries Basel, Beijing, Bochum, Bonn, Catania, Cracow, Dresden, Edinburg, Erlangen, Ferrara, Frankfurt, Genova, Giessen, Glasgow, GSI, Inst. of Physics Helsinki, FZ Jülich, JINR, Katowice, Lanzhou, LNF, Mainz, Milano, Minsk, TU München, Münster, Northwestern, BINP Novosibirsk, Pavia, Piemonte Orientale, IPN Orsay, IHEP Protvino, PNPI St. Petersburg, Stockholm, Dep. A. Avogadro Torino, Dep. Fis. Sperimentale Torino, Torino Politecnico,Trieste, TSL Uppsala, Tübingen, Uppsala, Valencia, SINS Warsaw, TU Warsaw, AAS Wien Spokesperson: Ulrich Wiedner - Uppsala Austria – Belaruz - China - Finland - France - Germany – Italy – Poland – Russia – Spain - Sweden – Switzerland - U.K. – U.S.A.. 3 new members Unfortunately we lost KVI.
Main Physics Goals Charmonium spectroscopy QCD exotics Hypernuclear Physics Charm in Nuclei … base program for the first few years.
The PANDA Detector
Layout of the detector (top view)
The Target Spectrometer
The Forward Spectrometer
Target Envisaged luminosity: L = 2 × cm –2 s –1 Required target thickness: 5 × cm –2 Luminosity: L = N pbar f x target Cluster jet target. Hydrogen pellet target. Targets for hypernuclear physics.
Beam pipe and pellet pipe
Reminder: Droplets, Pellets, etc. Liquified hydrogen (H 2 ) Temp K (T f =13.96 K) Through nozzle (d~12 μ m) Droplets formed (d=38 μ m) Cooling by evaporation Vacuum injection, freezing: Droplets now called pellets (d~20 μ m) H 2 molecules The WASA Pellet TargetThe hydrogen path Liquid phase observed, before and after vac. inj. [m]
Pellet target: working principle and result 1 mm
Pellet test station
Pressure - a measure for the pellet rate Experimental pellet distributions
Predicted beam pipe vacuum pumps at both ends of PANDA additional pumping between solenoid and dipole
Pellet tracking system under investigation: line scan camera provides online information on pellet position <100 µ m
Beam pipe pumping scheme
The Cluster Jet Target
The Cluster Jet Target Gas System
Targets for Hypernuclear Physics pp MC simulation of rescattering under large angles Primary target: Secondary target: stopping of
Stopping points for (INC calulations)
Secondary target: sandwich of C absorber and Si detectors
The Electromagnetic Calorimeter Required: Fast, high resolution scintillator for between 10 MeV - 2 GeV Two possible solutions: PbWO 4 (PWO) crystals BGO crystals lower light yield slower and more expensive Crystal size: 2 2 cm 2 22 X 0
PWO crystals light yield of PANDA crystals better than as CMS crystals
Light yield: temperature dependant
Optical Transmission of crystals from different suppliers
Optical transmission after irradiation
For comparison: BGO crystals 60 Co Light yield ~ 8 times higher than PWO
Readout device: APD CMS uses 5x5 mm 2 APDs For PANDA: 10x10 mm 2 APDs being developed by Hamamatsu Preliminary tests show no significant differences. Alternative readout devices like the PLANACON hybrid photomultiplier have been tested but show sensitivity to magnetic fields.
Expected performance (PWO calorimeter) Measurements with a tagged photon beam in Mainz: deposited energy / GeV t / ns
The Mechanical Design Barrel part: 2.5 m long, Ø 1.08 m, crystals End caps: upstream: Ø 0.68 m, 816 crystals downstream: Ø ~2 m, 6864 crystals Cooling to -25 C, temperature stabilized to ±0.1 C
Individual tapered crystals
Design to reduce # of crystal shapes
segmentation of the 160 crystals into 16 slices
Single alveoli pack
Dead space zones
Concept and major components of a barrel slice
End cap design
Implementation of the EMC into PANDA
The Forward EMC Shashlyk modules composed of lead absorbers and scintillators
Some benchmark channel simulation results
Charmed hybrid (J PC =1 –+ ) channel Production mode: pp g c ( ) S-wave J/ e + e – (µ + µ – )
Invariant mass spectra J/ cc gg
µ decay channel
Open charm channels D*(2010) + D*(2010) – D* ± D 0 ± D 0 decays
Reconstructed (4040) mass
Summary The PANDA collaboration is healthy and eagerly waiting to build up the experiment and to do world-class physics.