Presentation is loading. Please wait.

Presentation is loading. Please wait.

Marc Sangel Supervisor: Sebastian Johnert DESY Summer Student Programm Hamburg, DESY, 02. September 2011.

Similar presentations


Presentation on theme: "Marc Sangel Supervisor: Sebastian Johnert DESY Summer Student Programm Hamburg, DESY, 02. September 2011."— Presentation transcript:

1 Marc Sangel Supervisor: Sebastian Johnert DESY Summer Student Programm Hamburg, DESY, 02. September 2011

2 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 2 Outline Analysis Chain HepMCAnalysis ToolResults for different Generators Results for different PDFsEfficiencies Summary

3 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 3 Introduction

4 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 4 Analysis Chain Simulation Comparison with data Data Understanding signal and background processes LHC Search for new physics and particles

5 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 5 HepMCAnalysis Tool

6 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 6 HepMC Format > Graph structure of physics event > HepMC format: vertex and particle structure > Particles: kinematic information, ID, … > Each particle belongs at least to one vertex

7 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 7 HepMCAnalysis tool What is the HepMCAnalysis tool ? Framework for Monte Carlo generator validation and comparison Covers different aspects of event generation: hard process, UE, multiple parton interaction Covers many physics processes like pp->Z, pp->ttbar, pp- >W/Z +jets requirements Hardly dependency on other software packages User-friendly (many documentations, manuals, tutorials,…) Simple extendable for user analysis

8 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 8 Workflow of HepMCAnalysis

9 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 9

10 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 10 Results

11 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 11 Results for different generators: W histograms Hardly differences between Pythia6 and Pythia8 Higher differences between Herwig++ and Pythia Herwig++ does not decrease for first bin → will be checked

12 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 12 Pythia6 Herwig++ Pythia8

13 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 13 Results for different generators: charged stable particles peculiar behaviour of Pythia 8 Pythia 6 and Herwig++ very similar Pythia6 Herwig++ Pythia8 number

14 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 14 Parton Distribution Functions (PDFs) Usage of different orders leading order (LO): MSTW2008lo90cl next to leading order (NLO): CTEQ66 next to next to leading order (NNLO): HERAPDF15NNLOEIG modified leading order (LOmod): MRST2007lomod What is modified leading order? Want LO PDF to behave like NLO PDF Improvement of quality of LO global fit Relaxing the momentum sum rule at input Use NLO strong coupling for LO PDF

15 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 15 Results for Different PDFs: W histograms LO NLO NNLO LOmod (LO*)

16 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 16 LO NLO NNLO LOmod (LO*)

17 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 17 Results for different PDFs: Charged particles Again big differences for charged particle histograms LO NLO NNLO LOmod (LO*) number

18 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 18 Efficiency calculation

19 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 19 Results of efficiencies for different PDFs PDFEfficiencyError MSTW2008lo90cl0.127620.00119961 CTEQ66 (NLO)0.134820.00123692 HERAPDF15NNLOEIG0.134270.00123409 MRST2007lomod0.136170.00124383 PDFEfficiencyError MSTW2008lo90cl 0.085080.0008 CTEQ66 (NLO) 0.089880.000825 HERAPDF15NNLOEIG 0.0895130.000823 MRST2007lomod 0.090780.000829 ATLAS: Efficiency: 0.0975, Error: 0.0019; (arXive:1108.4101v1)

20 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 20 Summary Differences between LO and NLO PDFs Significant differences between PDFs and Generators for charged particles histograms Similar deviations for different tunes Efficiency similar to ATLAS results

21 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 21 Backup

22 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 22 Class Library

23 Marc Sangel | DESY Summer Student Programe | 2. September 2011 | page 23 Generators Pythia Hard process is calculated until leading order of parton distribution function Connection between partons (strings), to avoid free quarks Herwig Hard process also calculated until leading order All gluons decay in qqbar pairs. All quarks are composed in color neutral objects


Download ppt "Marc Sangel Supervisor: Sebastian Johnert DESY Summer Student Programm Hamburg, DESY, 02. September 2011."

Similar presentations


Ads by Google