1. Carsten Schwarz12.12.01 KP2 Physics with anti protons at the future GSI facility Physics program Detector set-up p e - coolerdetector High Energy Storage Ring HESR P max = 15 GeV/c L max = 2·10 32 cm -2 s -1 Ø < 100 μm Δ p/p < 10 -5 >> cooled anti protons >> internal target

2. Carsten Schwarz12.12.01 KP2 Physics program Charmonium spectroscopy Medium modifications of D mesons and J/Ψ in nuclei Hypernuclei CP violation Glueballs Hybrids

3. Carsten Schwarz12.12.01 KP2 Medium modifications of D mesons and J/Ψ in nuclei Continuation of present GSI physics FOPI, KAOS, HADES, …HESR Signal: medium modification of production threshold, resonance width e.g. Ψ, χ 2 Absorption cross section of J/Ψ in nuclei (ρ=ρ 0 ). pionic atoms KAOS/FOPI HESR π K D vacuumnuclear medium ρ = ρ 0 π+π+ π-π- K-K- K+K+ D+D+ D-D- 25 MeV 100 MeV 50 MeV ? Mass modifications of mesons

4. Carsten Schwarz12.12.01 KP2 Medium modifications Hayashigaki, Phys. Lett. B 487 (2000) 96Sibirtsev Nul. Phys. A 680 (2001) 274c Look eg. for decay of Ψ DD

5. Carsten Schwarz12.12.01 KP2 Charmonium gives information about QCD confinement potential. Many states are still missing. pp: direct population of all states. HESR allows investigation of states above DD threshold. Cooled beams with Δp/p10 -5 allow high precision scan of resonances. Charmonium spectroscopy 40 keV Crystal Ball e + e -

6. Carsten Schwarz12.12.01 KP2 Charmonium spectroscopy high resolution helps to identify states

7. Carsten Schwarz12.12.01 KP2 Glueballs Hybrids qqg ggg HybridGlueball Normal meson: 2 fermions P = (-1) L+1 C = (-1) L+S Excited glue: bosonic degree of freedom exotic quantum numbers eg. J PC =1 -+, 0 --, 0 +-, 2 +- … normal quantum numbers Signal: exotic quantum numbers: partial wave analysis normal quantum numbers: model comparison (LGT) mixing with normal mesons charm sector: few resonances with small widths qq Meson

8. Carsten Schwarz12.12.01 KP2 Glueball, Hybrids

9. Carsten Schwarz12.12.01 KP2 Hypernuclei - 3 GeV/c K+K Trigger _ secondary target - (dss) p(uud) (uds) (uds) study of interaction p

10. Carsten Schwarz12.12.01 KP2 CP violationin Hyperon decay p + p Λ +Λ pπ - pπ + Measure decay asymmetry of angular distribution of p relative to Λ-Hyperon momentum. I p (θ p ) ~ 1+α cos(θ p ) for Λ CP conservation: α = α Signal for CP violation: Theoretical prediction: ~10 -4 ~ 10 -5 Experiment: 10 10 reconstructed ΛΛ L=2·10 32 cm -2 s -1 >1 year running

11. Carsten Schwarz12.12.01 KP2 Detector requirements (simulations) Energy release of charmed hadrons high large p trans large angles High cm-velocity (fixed target) high energies small angles Formation of Ψ and decay in muons Ψμ + μ - ΨJ/Ψ + X μ + μ - electrons similar calorimeter for large angles.

12. Carsten Schwarz12.12.01 KP2 Detector requirements (PID) Forward angles need π/K separation up to 3 GeV/c: Cherenkov n=1.02 Backward: higher value of n. p+p ΦΦ 4K s ½ =3.6 GeV

13. Carsten Schwarz12.12.01 KP2 HESR-detector Internal target forward spectrometertarget spectrometer Heavy charmed mesons decay in light products with large p t. Solenoid is important. top view

14. Carsten Schwarz12.12.01 KP2 HESR detector side view

15. Carsten Schwarz12.12.01 KP2 Central tracking: Microvertex Detector 7.2 mio. barrel pixels 50 x 300 μm 2 mio. forward pixels 100 x 150 μm beam pipe pellet pipe Readout: ASICs (ATLAS/CMS) 0.37% X 0 or pixel one side – readout other side (TESLA)

16. Carsten Schwarz12.12.01 KP2 MVD single track resolution (Geant 4) σ D0 =51 μm σ Z0 =82 μm x y z D0D0 Z0Z0 p 8.5 GeV 2π + 2π - Vertex resolution is sufficient for D-physics c (D ) = 314 μm, c (D 0 ) = 124 μm

17. Carsten Schwarz12.12.01 KP2 TS momentum resolution (Geant 4) MVD straw tubes MDC pp( s = 4.4 GeV/c 2 ) J/ σ M = 1.2% ???

18. Carsten Schwarz12.12.01 KP2 Particle identification PID from 0 0 <Θ<5 0 hadronic calorimeter 5 0 <Θ<22 0 Aerogel Cherenkov Counters 22 0 <Θ<140 0 DIRC (BABAR@SLAC) DIRC thickness: 0.19 X 0

19. Carsten Schwarz12.12.01 KP2 B = 0 Tesla: Cherenkov opening angle: Internal reflection different vel. thresholds DIRC PID B = 2 Tesla: Azimuthal deflection more homogeneous detection efficiency

20. Carsten Schwarz12.12.01 KP2 DIRC PID (Geant4) p p( s = 3.6 GeV/c 2 ) misidentification of π as K K efficiency PID+tracking

21. Carsten Schwarz12.12.01 KP2 Calorimeter PbWO 4 Length = 17 X 0 APD readout (in field) σ(E) = 1.54% / E ½ + 0.3% pp J/Ψ + η γγ 140 o 5o5o 22 o

22. Carsten Schwarz12.12.01 KP2 e ± /π ± sep. electron/pion separation 10 -3 2468 p (GeV/c) 0 E dep (GeV/c) 2 4 6 8 10 e +/- π+π+ 2468p (GeV/c)0 10 -3 π + probability

23. Carsten Schwarz12.12.01 KP2 Pellet target Frozen hydrogen pellets 20-40μm Δx=±1 mm (±0.04 o ) 60 m/s 70000 pellets/sec. 10 14 -10 16 atoms/cm 2 (avg.) 1 mm

24. Carsten Schwarz12.12.01 KP2 Costs Solenoid 2.5 M Calorimeter (target) 12.5 M Tracking ( pixel detector, straw tubes) 3.0 M Cherenkov 3.5 M Hypernuclei ( read out electronics,micro tracker) 2.0 M Varia 1.9 M Trigger 1.5 M Infrastructure 2.0 M Contingency 2.0 M Sum 30.9 M

25. Carsten Schwarz12.12.01 KP2 Collaborations: Working group: LEAR, COSY, SATURNE community MunichGermany Bochum Giessen Dresden Erlangen Jülich FerraraItaly Turin KrakowPoland Warsaw T. BarnesD. Bettoni R. CalabreseM. Düren S. GanzhurV. Hejny H. KochU. Lynen V. MetagH. Orth S. PaulK. Peters J. PochodzallaJ. Ritman L. SchmittC. Schwarz K. SethW. Weise U. Wiedner

26. Carsten Schwarz12.12.01 KP2