Simulation studies of the PANDA detector at GSI

Transcription

1 Simulation studies of the PANDA detector at GSI Carsten Schwarz for the Antiproton Physics Study Group PANDA = Proton ANtiproton at DArmstadt Introduction HESR (High Energy Storage Ring) Physics program Simulation of Detector components Micro Vertex Tracker Straw Tube Tracker DIRC RICH Calorimeter Summary & Outlook

2 GSI HESR High Energy Storage Ring Momenta GeV/c Spread (<8 GeV/c) Beam Ø 100 um p stored in ring 5 x L (pellet target) 2 x cm -2 s -1 Int. L 10 pb -1 /day

3 Physics Program Charmonium spectroscopy Glueballs Hybrids Medium modifications of D mesons and J/Ψ in nuclei CP violation Hypernuclei

4 Simulation framework: C++ Geant4 Root Event Generation DPM pbar+p background UrQMD pbar+a PndEvtGen (Pluto) PndSimApp GEANT4 modelling of the detector PndRecoApp Tracking, EMC-cluster finding, RICH rings... PandaApp 'user analysis', PID, spectra Full simulation Fast simulation

5 Angular Acceptance Formation of ψ and decay in muons ψ µ + µ - µ + µ - ψ J/ψ + X similarly electrons: -->for large angles calorimeter needed.

6 PANDA Detector Target spectrometer Forward spectrometer

7 Micro Vertex Detector (MVD) 7.2 mio. barrel pixels 50 x 300 µm pellet pipe beam pipe 2 mio. forward pixels 100 x 150 µm Layers 5 barrel, 5 endcap thickness 200 µm thick. 5 layers % X 0 resolution σ φz µm Readout: ASICs (ATLAS/CMS) 0.37% X 0 or pixel one side - readout other side (TESLA)

8 MVD geometry y D 0 z Z 0 x

9 Geant4 and multiple scattering MeV pc z x X ln x X 0

10 Straw tubes DIRC STT MVD Number of double layers Skew angle of double layers 1 and 15 Skew angle of double layers 2-14 Straw tube wall thickness Wire thickness Gas Length Diameter of tubes in double layers 1-5, 6-10, and Number of straw tubes 15 0 o 2 o -3 o Transverse resolution σ x,y 150 µm Longitudinal resolution σ 1 mm z 26 µm 20 µm 90%He+10%C 4 H cm 4, 6, 8 mm 8734 Event example: pp --> φφ --> 4K

11 DIRC Detecting Internally Reflected -light PID: tracking --> p, RICH --> β --> m less space than aerogels costs of calorimeter no problems with field

12 DIRC degree degree degree degree K eff. χ 2 /n=2.4 pion beta= photons π miss-id. reaction pp φφ at s = 3.6 GeV/c 2

13 T1 T2 DIRC Time Of Propagation (discussed at Belle) T, reduced # of PMT for Kaon PID very good time resolution required (~ 100 ps)

14 DIRC radiator quality Edge losses Edge thickn. Sharpness of edges should be 50 µm

15 Forward RICH Search for good combination radiator photon detector magnetic field Aerogel (n=1.02) visible light PD HPD C 6 F 14 (n=1.24) CsI coated photo cath. (λ < 210 nm = UV) 4 10 cm Proximity "focussing" compact detector

16 Aerogel and Rayleigh scattering Aerogel C 6 F 14 Photon # generated Det. Eff. Rayleigh scattered Detected Wavelength [nm] Wavelength [nm] Combination of aerogel radiator and CsI-photo cathode is not working. Visible light???

17 Forward RICH LHCb Multi pad gas Detector Mismatch photons<-> CsI photon conversion Aerogel n=1.02 proximity focusing mirrors

18 Calorimeter PbWO 4 Length = 17 X 0 APD readout (in field) σ(e) = 1.54% / E ½ + 0.3% (PM) pp J/ψ + η γγ

19 Summary & Outlook Status Design of PANDA for GSI Future Project Simulations in a framework of C++, Geant4, and ROOT Target spectrometer nearly implemented Future tasks Completion of detector implementation (forward spectrometer) Intensive background simulations Annihilations ~ 100 mb Reactions nb need 10 8 events for each valid event to prove background supression --> fast simulation

20 Antiproton Physics Study Group T. Barnes 1, D. Bettoni 2, R. Calabrese 2, W. Cassing 3, M. Düren 3, P.Thörngren Engblom 4, S. Ganzhur 5, A. Gillitzer 6, O. Hartmann 7, V. Hejny 6, P. Kienle 8, H. Koch 5, W. Kühn 3, Agnes Lundborg 9, Elin Lundström 9, U. Lynen 7, R. Meier 10, V. Metag 3, P. Moskal 6, Örjan Nordhage 9, H. Orth 7, S. Paul 8, K. Peters 5, J. Pochodzalla 11, J. Ritman 3, Y. Rogov 12, H. Rohdjess 13, M. Sapozhnikov 12, L. Schmitt 8, 7, K. Seth 14, A. Sokolov 7, V. Uzhinsky 12, N. Vlassov 12, W. Weise 8, U. Wiedner 9 1) University of Tennessee, Knoxville 2) INFN, Ferrara 3) Universität Gießen 4) Uppsala University 5) Experimentalphysik 1, Bochum 6) Institut für Kernphysik, FZ Jülich 7) GSI Darmstadt 8) Technische Universität München 9) ISV, Uppsala 10) Physikalisches Institut, Tübingen 11) Institut für Kernphysik, Mainz 12) JINR, Dubna 13)Universität Bonn 14) Northwestern University, Evanston