C. Schwarz Physics with Antiprotons - Detector - Detector requirements Overview of the detector concept Selected detector components Simulations

C. Schwarz 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 Ψ’→μ + μ - Ψ’→J/Ψ + X ↓ μ + μ - electrons similar → calorimeter for large angles.

C. Schwarz 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

C. Schwarz Overview of detector concept internal target forward spectrometertarget spectrometer Heavy charmed mesons decay in light products with large p t. Solenoid is important. top view

C. Schwarz Overview of detector concept side view

C. Schwarz 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)

C. Schwarz 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

C. Schwarz TS momentum resolution (Geant 4) MVD straw tubes MDC pp(  s = 4.4 GeV/c 2 )  J/  σ M = 1.2% ???

C. Schwarz 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 DIRC thickness: 0.19 X 0

C. Schwarz B = 0 Tesla: Cherenkov opening angle: Internal reflection → different vel. thresholds DIRC PID B = 2 Tesla: Azimuthal deflection → more homogeneous detection efficiency

C. Schwarz DIRC PID (Geant4) p p(  s = 3.6 GeV/c 2 )    misidentification of π as K K efficiency PID+tracking

C. Schwarz 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

C. Schwarz e ± /π ± sep. electron/pion separation  p (GeV/c) 0 E dep (GeV/c) e +/- π+π+ 2468p (GeV/c) π + probability

C. Schwarz Pellet target Frozen hydrogen pellets 20-40μm Δx=±1 mm (±0.04 o ) 60 m/s pellets/sec atoms/cm 2 (avg.) 1 mm