1. Simulating the mass spectrum of J/Ψ  and Upsilon Ingrid von Glehn Angus Comrie University of Cape Town Supervisor: Galina Shabratova Veksler and Baldin Laboratory of High Energy Physics

2. ALICE ► Detector at LHC ► Studies heavy-ion collisions ► Large number of subdectectors ► UCT-CERN group focuses on Dimuon

3. MUON Detector

4. Grid Computing ► Large data volume from experiment ► Can be processed independently ► Split up tasks across processors in an organised fashion (tier model)‏ ► ALICE Grid (ALIEN)‏

5. J/Ψ  Suppression as a sign of QGP

6. Simulation ► ROOT: C++ interpreter and analysis package ► Pythia: Particle transport / event simulation ► AliROOT: Contains geometry of entire ALICE project

7. Simulating the mass spectrum of J/Ψ  and Upsilon  ► Generate events using Pythia, only consider dimuon decays ► Apply Gaussian smearing to angles and momentum of muon pair ► Smeared mass histogram

8. Results for J/Ψ  (1000 events)‏

9. Results for Upsilon (50000 events)‏

10. Background for charm pair ► More realistic situation, consider more decays ► Get an idea of what to expect ► Can look at particle code histogram to see major decays

11. Background for charm pair π0π0 π±π± strange mesons eg. K charmed mesons eg. D c,c μ±μ±

12. Background

13. ALICE Experiment ► Can compare simulated data with experimental data ► Can simulate different decay processes and see which agrees with experiment ► Comparison of theoretical models