1 / 14

Paul Szczypka & Qingying Jia

Comparison of Monte Carlo event generators at LHC energies. Paul Szczypka & Qingying Jia. Highlight main difference between Pythia and Phojet Compare Pythia and Phojet minimum bias events Compare Pythia and Phojet B0 events Compare Pythia v6.205 with v6.222. Preview.

dionne
Download Presentation

Paul Szczypka & Qingying Jia

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Comparison of Monte Carlo event generators at LHC energies Paul Szczypka & Qingying Jia

  2. Highlight main difference between Pythia and Phojet Compare Pythia and Phojet minimum bias events Compare Pythia and Phojet B0 events Compare Pythia v6.205 with v6.222 Preview

  3. PHOJET and PYTHIA use different theoretical models to deal with the low pt problems • Phojet combine the DPM on soft processes with the predictive power of perturbative QCD, the event generator is formulated as a two-component model (soft and hard). The basic process is 2 → n. • Pythia Attempt to extend perturbative (high-pt) picture down to low-pt region. The basic processes is 2 → 2 with the usual LO matrix elements.

  4. PHOJET • Based on the Dual Parton Model with a smooth transition between the soft and the hard region at • distribution sampled from an exponential distribution:

  5. ATLAS investigation

  6. Notes: Phojet v1.12 vs. Pythia 6.205 – minimum bias • Reasonable fit • Phojet ‘out of box’ • <n>: • Phojet = 20.32 • Pythia = 21.87 • O(10%) difference

  7. Notes: Pythia v6.222 vs. Pythia 6.205 – minimum bias • 6.222 latest release • No obvious difference • Same tuning

  8. Pythia v6.222 vs. Pythia v6.205 – B0 event data Notes: • 6.222 latest release • Good fit B0 event distributions 1

  9. Pythia v6.222 vs. Pythia v6.205 – B0 event data Notes: • 6.222 latest release • Good fit 2

  10. Pythia v6.222 vs. Pythia v6.205 – B0 data Notes: • 6.222 latest release • Good fit B0 distributions 1

  11. Pythia v6.222 vs. Pythia v6.205 – B0 data Notes: • Forced B0 • 6.222 latest release • Good fit 2

  12. Phojet v1.12 vs. Pythia v6.205 – B0 data Notes: • Phojet untuned • Phojet multiple interactions on • Softer PT • B0 pseudorapidity different • Both B0 production cross sections within 5%

  13. Phojet v1.12 vs. Phojet v1.12 – B0 data Notes: • Believe B0 created from soft interaction • Understand central region production • Requires investigation

  14. Pythia v6.222 closely reproduced v6.205 data Phojet v1.12 produces similar distributions to Pythia v6.205 for min bias Phojet v1.12 produces softer PT B0 particles The soft mechanism produces B0 in Phojet – needs further study Need to understand pseudorapidity distributions of B0 Summary

More Related