Simulation in Particle Physics David Grellscheid What are the - PowerPoint PPT Presentation

Simulation in Particle Physics David Grellscheid

What are the fundamental building blocks of Nature?

T-Shirt, explain rules here

T-Shirt, explain rules here

4e candidate with m 4e = 124.6 GeV p T (electrons)= 24.9, 53.9, 61.9, 17.8 GeV m 12 = 70.6 GeV, m 34 = 44.7 GeV 12 reconstructed vertices ATLAS: Status of SM Higgs searches, 4/7/2012 37

Theory Experiment

? Theory Experiment

Proton bunches 25 ns apart 11 10 protons per bunch ~25 collisions per crossing

~100 million readout channels, every 25 ns

CMS

CMS After zeroes removed, 1.6 MB / event 


CMS After zeroes removed, 1.6 MB / event 
 * 40 M events / s = 64 TB / s ?

CMS After zeroes removed, 1.6 MB / event 
 * 40 M events / s = 64 TB / s ? Can’t save everything

Trigger system to keep only interesting events Incoming event rate per second Outgoing event rate per second Reduction factor Level 1 40 000 000 100 000 400 Level 2 100 000 3 000 30 Level 3 3 000 200 15

Trigger system to keep only interesting events Incoming event rate per second Outgoing event rate per second Reduction factor Level 1 40 000 000 100 000 400 Level 2 100 000 3 000 30 Level 3 3 000 200 15 200 events / s * 1.6 MB / event = 320 MB / s

Trigger system to keep only interesting events Incoming event rate per second Outgoing event rate per second Reduction factor Level 1 40 000 000 100 000 400 Level 2 100 000 3 000 30 Level 3 3 000 200 15 200 events / s * 1.6 MB / event = 320 MB / s = ~ 3200 TB / year raw data

Trigger system to keep only interesting events Incoming event rate per second Outgoing event rate per second Reduction factor Level 1 40 000 000 100 000 400 Level 2 100 000 3 000 30 Level 3 3 000 200 15 200 events / s * 1.6 MB / event = 320 MB / s = ~ 3200 TB / year raw data Analysis is done offline, 
 ~3000 collaboration members should have equal access to data worldwide

-1 -1 CMS Preliminary s = 7 TeV, L = 5.05 fb ; s = 8 TeV, L = 5.26 fb Events / 3 GeV Events / 3 GeV 2011+2012% 12 12 7 TeV 4e, 4 µ , 2e2 µ Data 8 TeV 4e, 4 , 2e2 µ µ Z+X 10 10 Z *,ZZ � 8 8 m =126 GeV H 6 6 4 4 2 2 0 0 m m [GeV] [GeV] 4l 4l μ μ 80 100 120 140 160 180 m [GeV] 4l ATLAS: Status of SM Higgs searches, 4/7/2012

Re -1 -1 CMS Preliminary s = 7 TeV, L = 5.05 fb ; s = 8 TeV, L = 5.26 fb Events / 3 GeV Events / 3 GeV 2011+2012% 12 12 7 TeV 4e, 4 µ , 2e2 µ Data 8 TeV 4e, 4 , 2e2 µ µ Z+X 10 10 Z *,ZZ � 8 8 m =126 GeV H 6 6 � 4 4 2 2 0 0 m m [GeV] [GeV] 4l 4l μ μ 80 100 120 140 160 180 m [GeV] 4l ATLAS: Status of SM Higgs searches, 4/7/2012

Re Need to get theory -1 -1 CMS Preliminary s = 7 TeV, L = 5.05 fb ; s = 8 TeV, L = 5.26 fb Events / 3 GeV Events / 3 GeV 2011+2012% 12 12 predictions. 7 TeV 4e, 4 µ , 2e2 µ Data 8 TeV 4e, 4 , 2e2 µ µ Z+X 10 10 Z *,ZZ � 8 8 m =126 GeV H 6 6 � 4 4 2 2 0 0 m m [GeV] [GeV] 4l 4l μ μ 80 100 120 140 160 180 m [GeV] 4l ATLAS: Status of SM Higgs searches, 4/7/2012

Re Monte Carlo event generators �

Herwig details • General purpose MC event generator • 30-year history in its F77 implementation; 
 Herwig 7 is a complete redesign from ground up in 
 C++, started 2003. (more and more python creeping in) • currently ~15 collaboration members 
 in Durham, Karlsruhe, Manchester, Zurich • Coordination is hard. Technically: Trello / Trac / Jenkins. 
 Don’t have a good model sociologically. • Main reference: arXiv:0803.0883, 1101.2599 
 https://herwig.hepforge.org/

ThePEG Herwig++ Toolkit for high energy physics event generation [Leif Lönnblad] Box of physics implementations Each building block is 
 a compiled C++ class

ThePEG Repository plaintext setup files no more compilation needed here

Default Setup EventGenerator RNG Physics Model EventHandler Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization

Default Setup EventGenerator create ThePEG::StandardEventHandler /Herwig/LHCHandler set LHCHandler:LuminosityFunction FixedLHCLuminosity insert LHCHandler:SubProcessHandlers[0] /Herwig/SimpleQCD RNG Physics Model set LHCHandler:CascadeHandler /Herwig/ShowerHandler set LHCHandler:HadronizationHandler /Herwig/ClusterHadHandler set LHCHandler:DecayHandler /Herwig/DecayHandler [...] EventHandler create ThePEG::EventGenerator /Herwig/LHCGenerator ThePEG.so 
 set LHCGenerator:EventHandler /Herwig/LHCHandler 
 [...] Parton 
 Hadron- 
 Hard 
 Decays set LHCHandler:BeamA /Herwig/Particles/p+ Subprocess Shower ization set LHCHandler:BeamB /Herwig/Particles/p+ set FixedLHCLuminosity:Energy 14000.0 [...]

Default Setup EventGenerator create ThePEG::StandardEventHandler /Herwig/LHCHandler set LHCHandler:LuminosityFunction FixedLHCLuminosity insert LHCHandler:SubProcessHandlers[0] /Herwig/SimpleQCD RNG Physics Model set LHCHandler:CascadeHandler /Herwig/ShowerHandler set LHCHandler:HadronizationHandler /Herwig/ClusterHadHandler set LHCHandler:DecayHandler /Herwig/DecayHandler [...] EventHandler create ThePEG::EventGenerator /Herwig/LHCGenerator ThePEG.so 
 set LHCGenerator:EventHandler /Herwig/LHCHandler 
 [...] Parton 
 Hadron- 
 Hard 
 Arbitrary user extensions use dlopen(): Decays set LHCHandler:BeamA /Herwig/Particles/p+ Subprocess Shower ization set LHCHandler:BeamB /Herwig/Particles/p+ create DGrell::Myclass /DGrell/Myclass DGrellHwPlugin.so set FixedLHCLuminosity:Energy 14000.0 [...] Main code never needs recompilation.

Default Setup EventGenerator create ThePEG::StandardEventHandler /Herwig/LHCHandler set LHCHandler:LuminosityFunction FixedLHCLuminosity insert LHCHandler:SubProcessHandlers[0] /Herwig/SimpleQCD RNG Physics Model set LHCHandler:CascadeHandler /Herwig/ShowerHandler set LHCHandler:HadronizationHandler /Herwig/ClusterHadHandler set LHCHandler:DecayHandler /Herwig/DecayHandler [...] EventHandler create ThePEG::EventGenerator /Herwig/LHCGenerator ThePEG.so 
 set LHCGenerator:EventHandler /Herwig/LHCHandler 
 [...] Parton 
 Hadron- 
 Hard 
 Decays set LHCHandler:BeamA /Herwig/Particles/p+ Subprocess Shower ization set LHCHandler:BeamB /Herwig/Particles/p+ set FixedLHCLuminosity:Energy 14000.0 [...]

Default Setup EventGenerator RNG Physics Model EventHandler Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization

Event record flow ∅ Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization Herwig 
 Analysis

Event record flow ∅ Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization Herwig 
 Analysis HepMC other 
 Rivet users LHC 
 expts

Event record flow ∅ Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization Herwig 
 Analysis HepMC other 
 Rivet users LHC 
 expts

Event record flow ∅ Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization LHE 
 Herwig 
 hand-coded 
 2 → 2 ME 
 file reader Analysis MEs 
 construction (hel. amplitudes) HepMC other 
 Rivet users LHC 
 expts

Event record flow ∅ Parton 
 Hadron- 
 Hard 
 Decays Subprocess Shower ization LHE 
 Herwig 
 hand-coded 
 2 → 2 ME 
 file reader Analysis MEs 
 construction (hel. amplitudes) HepMC UFO other 
 Rivet users LHC 
 expts

Simulated data sets of millions of events