EIC Monte Carlo and the Question of Jets

1. EIC Monte Carlo and the Question of Jets Joseph Seele University of Colorado at Boulder seele@down.colorado.edu Second Electron-Ion Collider Workshop - March 16, 2004 Jefferson Lab

2. Outline • Monte Carlo • History of Development • Basic Structure • Current State • Question of Jets • Events Displays of e-p from MC at • 10 GeV on 50 GeV • 10 GeV on 150 GeV • 10 GeV on 250 GeV • Hadronic Angular Distributions of Event Samples Second Electron-Ion Collider Workshop Joseph Seele

3. History of the Monte Carlo The physics monte carlo was primarily derived from the HERMES monte carlo Naomi Makins (UIUC) Antje Bruell (JLab) Joseph Seele (Colo.) EIC Second Electron-Ion Collider Workshop Joseph Seele

4. History of the Monte Carlo An elementary detector simulation was built in ELECTRA, a GEANT based system Bernd Surrow (MIT) poof! Second Electron-Ion Collider Workshop Joseph Seele

5. Structure of the Monte Carlo The physics monte carlo consists of a framework called GMC (Generator Monte Carlo) inside which a simulation, based on either external or internal calculations, is built. GMC physics calculations data Second Electron-Ion Collider Workshop Joseph Seele

6. Structure of theMonte Carlo • There are three current simulations based on separate packages • disNG – (deep inelastic scattering Next Generation) This is an internal • code built originally for HERMES, but then adapted to a colliding • beam experiment setup for EIC. • pepsi4 – (polarized electron-proton scattering interactions) A standard • external package for polarized electron proton scattering. • aroma – An external package to simulate the production of heavy quarks • in electron proton scattering through boson-gluon fusion. • (insert your generator here) Second Electron-Ion Collider Workshop Joseph Seele

7. Current State of Development pythia6 ep scattering ho! Next to Corral heavy quarks don’t stand a chance here I come EIC! dev. proceeding pepsi4 then on to aroma disNG RAPGAP Current Team Second Electron-Ion Collider Workshop Joseph Seele

8. Question of Jets • The possibility of jets in EIC was explored in the MC using disNG at 3 collision energies with unpolarized species. • 10 GeV on 50 GeV • 10 GeV on 150 GeV • 10 GeV on 250 GeV • W2 > 4.0 and Q2 > 0.5 were used in the analysis. Second Electron-Ion Collider Workshop Joseph Seele

9. 10 GeV on 50 GeV Event Displays Most events look like this one Second Electron-Ion Collider Workshop Joseph Seele

10. 10 GeV on 50 GeV Event Displays Second Electron-Ion Collider Workshop Joseph Seele

11. 10 GeV on 50 GeV Event Displays Second Electron-Ion Collider Workshop Joseph Seele

12. 10 GeV on 50 GeV Event Displays Second Electron-Ion Collider Workshop Joseph Seele

13. 10 GeV on 150 GeVEvent Displays Again most events look like this one Second Electron-Ion Collider Workshop Joseph Seele

14. 10 GeV on 150 GeVEvent Displays Second Electron-Ion Collider Workshop Joseph Seele

15. 10 GeV on 150 GeVEvent Displays Second Electron-Ion Collider Workshop Joseph Seele

16. 10 GeV on 150 GeVEvent Displays Second Electron-Ion Collider Workshop Joseph Seele

17. 10 GeV on 250 GeVEvent Displays Again most events look like this one Second Electron-Ion Collider Workshop Joseph Seele

18. 10 GeV on 250 GeVEvent Displays Second Electron-Ion Collider Workshop Joseph Seele

19. 10 GeV on 250 GeVEvent Displays Second Electron-Ion Collider Workshop Joseph Seele

20. 10 GeV on 250 GeVEvent Displays Second Electron-Ion Collider Workshop Joseph Seele

21. Theta DistributionsDefinition of Theta scattered electron hadrons q x incident electron incident proton z (target) (beam) y Essentially q is the angle that the hadrons’ momentum vectors make with the momentum vector of the incident electron. Second Electron-Ion Collider Workshop Joseph Seele

22. Theta Distribution at10 GeV on 50 GeV <q>=2.643 RMS=.7623 The red lines indicate a 3o acceptance on either side of the detector Second Electron-Ion Collider Workshop Joseph Seele

23. Theta Distribution at10 GeV on 150 GeV <q>=2.751 RMS=.6971 The red lines indicate a 3o acceptance on either side of the detector Second Electron-Ion Collider Workshop Joseph Seele

24. Theta Distribution at10 GeV on 250 GeV <q>=2.801 RMS=.6520 The red lines indicate a 3o acceptance on either side of the detector Second Electron-Ion Collider Workshop Joseph Seele

25. Conclusions • Monte Carlo • Development is proceeding with Pythia6. • Development then to shift to RAPGAP. • The MC and all its documentation can be found at http://www.npl.uiuc.edu/~eic for anyone interested in performing simulations. • If you are interested in helping with development please contact myself (seele@down.colorado.edu), Naomi Makins (makins@uiuc.edu) or Antje Bruell (abr@lns.mit.edu) • Question of Jets • The uncertainty about whether we can speak of jets or not depends on the definition that we wish to use for a jet. • The issue is not completely closed though. I would like to see a more quantitative assessment (and plan on performing one). Second Electron-Ion Collider Workshop Joseph Seele