1. Principle Simulations for Detector Concepts at HESR Goals Methods Current Status Application to p + p   ´(3686) GSI Workshop on its Future Facility 18.10.2000 J.Ritman Uni. Gießen

2. Goals Fast Simulation Environment Able to evaluate many different configurations and do multiple iterations Correct Kinematics Background Evaluation Determine the required resolution and rate capabilities Study trigger concepts (e.g.  -Cha, RICH, multiplicity jump near vertex)

3. Methods ROOT as framework PLUTO++ as event generator http://www-hades.gsi.de/computing/pluto/html/PlutoIndex.html (Marios Kagarlis) Pseudo-Tracking –Correct treatment of motion and decays in magnetic fields. –Parameterizations of detector efficiencies and resolutions.

4. HESR Detector Concept

5. Results for p p   ´(3686) Signal: (235 nb) p + p   ´  e + e - (0.88%)  +  - (1.03%) J/  +  - (31%) J/  2  o  (18.2%) J/  (2.7%) 2  + 2  -  0 (0.35%) 2  + 2  -  0 (0.3%) Background: (  tot =56mb)  +  -  (4  b)  +  - +  o  (40  b)  +  - +  (5  b)  +  - +  o  (15  b)  +  - +   (60  b)  +  - +  (10  b)  +  - +  o  o (200  b)  +  - +  +  - (30  b)  +  - +  o  +  - (400  b)

6. Muon Phase Space Distributions J/   +  - Generated Detected ‘+-‘+-

7. Expected Signal for 1 pb -1 Combinatorial background in events with  ‘ formation

8. Background from  and  Decay (  are mostly stopped before they decay) P(  ) ~ 0.004

9. Kaon Identification Reaction: p(8.5GeV)+p  X(M=4.4GeV)  J/  + 

10. Conclusions Simulations group being formed Fast simulation package exists 1st iteration for HESR detector Connection to GEANT4 being implemented (V.Hejny FZ-Jülich)