1. Detector Concepts Target/Luminosity Additions: Recoil detector
Fritz-Herbert Heinsius (Universität Freiburg)
Target/Luminosity
COMPASS detector
New proposals
STORS (I.Savin)
Additions:
Recoil detector
protons
neutral particels
Electromagnetic calorimeter
Particle Id?
Acceptance?
Trigger?

2. Target and Luminosity Unpolarized:
2.5m LH2: L= cm-2s-1
2.5m LD2: L= cm-2s-1
8 cm Cu: L= cm-2s-1
Polarized (f=0.4, Pb=0.8, Pt=0.5, D(y)):
1.2m 6LiD: L= cm-2s-1 (r=0.54 g/cm3)
Assuming µ per burst (16.8s cycle)
Absolute luminosity determination: 1% ?
Beam sport RMS: horiontal 4.5mm, vertical 7.5 mm (DVCS)

3. COMPASS Spectrometer 2003/04
1 Tm
4.4 Tm

4. Resolution and acceptance
µ´: Q2 = 10-4 – 100 GeV2/c2
x = 10-5 – ~0.4 (1)
eff(P) = 0.9(5 GeV), 0.75(1.5), 0.5(0.8)
E>20 MeV
ECAL dE/E= / sqrt(E)
position = 6.0 / sqrt(E) mm E>20 MeV
≤180 mrad
µ: Dp/p = 0.5 %
Hadron: p=1-200 GeV/c
Dp/p ~ 0.5 % at 15GeV/c
K/p: 9 – 40 GeV/c

5. 160 GeV/c

9. Particle Identification
q(mrad)
p(GeV/c) p K
p, m
With RICH
and hadron calorimeters
hadrons m
Essential for
reconstruction
of D-Mesons

10. New Technologies for Tracking and Particle ID
GEM
Large area
drift detectors
MicroMegas
Scintillating fiber trackers
TDC
RICH
CsI & MWPC readout
Radiator: C4F10
Readout electronics

11. COMPASS Acceptance

12. High pT cuts