Physics Generation for Atlas Data Challenges

Continuously updated/always incomplete
Last update November 19 2004

Production has finished.

In releases prior to 8.0.4 there is a confict between tauola and atlfast which prevents them being run in the same job. This is fixed in 8.0.4 and later. There are no other code changes between 8.0.1 and 8.0.x that affect event generation.
Note that the samples made with MC@NLO contain weighted events. You must use the event weight (which is found in EventInfo) when making plots (hf1(your thing, wt)). Some versions of atlfast do not use the weights in the ntuples. These ntuples are therefore unphysical

This page deals only with generation issues. For simulation and reconstruction go here

Ian Hinchliffe


Link to DC0 and DC1 information

Generator Software status in releases 
Contact persons  
HLT Streams

DC2

General comments



The 10M event sample for Tier0/Tier1 test of DC2.

This 10M event sample will satisfy the  requirement of many trigger streams and a fairly rich sample without
having too much bias in the physics. There are  two classes of events.  Events in class B have a much larger cross-section. The numbers below are the number of events and the bias that must be put back to restore the true cross-sections.: sigma =Nevents/bias. We have too many top and too few W_jets events for example. Its normalized to the Z rate. Note that within each class the biases are very similar, so that the unbiased stream is almost realistic within each class. There is no way to avoid the large difference in biases between the two classes. If the class B events are filtered out, then a reasonable physics sample is left.

Events will be generated and saved as Pool files.

Samples that require filtering will have the filter applied after the Pool file is read and before simulation is run. The samples that are to be filtered in this way are B4, B5 and H1-H9. Larger samples must be generated in these cases.

Some of the samples need external event files at generation time. These are A0, A4, A5 A7. In these cases, sample files are in the cvs  area. For intructions where to the the rest, please read this file

Note that this is the final layout (not the initial layout) and that single particle samples are not listed here.
Production of these samples is expected to  begin in tomorrrow.

 
After the events are generated, the atlfast ntuples are looked at by someone in the appropriate physics group. As part of this I am asking people to fill in the HLT table below .

After the "sign off" events go to simulation.



Class A:

A0: 1M top (bias=2.92 )   MC@NLO (+herwig)  used . Tauola is on. THIS SET IS DONE.
A0a: Note that 0.5M of these top events will be also be simulated with misalignment

A1: 1M Z (to ee), no pt cut. (bias=1) Pythia . THIS SET IS BEING GENERATED: TEST FILE HAS BEEN VALIDATED
A2: 1M Z (to mumu ), no pt cut. (bias=1), Pythia .   THIS SET IS DONE. TEST FILE HAS BEEN VALIDATED
A3:
1M Z (to tau tau), no pt cut. (bias=1), Pythia.  Note that Tauola is on  THIS SET IS DONE. TEST FILE HAS BEEN VALIDATED
A4: 1M W (to leptons) MC@NLO (+herwig)  used as this will give good representation of W+2 jets. For this sample the W decays have to be generated separately. Therefore this sample consists of six subsamples for W+ decaying to e, mu and tau and W- decaying to e, mu and tau. There should be  167K of each.  THIS SET IS DONE using 8.0.5 or 8.0.4 with GeneratorOptionsDC2-00-00-11
A5: 0.5M Z+jet sample.  Z decays to leptons only (including neutrinos). Made with Madcup and hadronized with Pythia. THIS SET IS READY TO START GENERATION.TEST FILE HAS BEEN VALIDATED
A6: 0.25M dijets (pt>600) (bias=1.36) THIS SET IS READY TO START GENERATION
A7: 0.25M W(to leptons) +4 jets with Alpgen and Pythia  Approximate cuts are  p_T>15 GeV for jets and leptons THIS SET IS DONE
A8: 0.5M QCD events filtered to provide a sample with at least 1 b-jet with pt>15 and eta<2.5  Note that no additional filtering is required after generation. THIS SET IS DONE. TEST FILE HAS BEEN VALIDATED
A9: 200K susy coannihilation point.  THIS SET IS DONE. (note that tauola is OFF  due to a possible problem with the tauola interface in susy events). The Physics/GeneratorOptionsDC2/share files changed on June 11 (tag GeneratorOptionsDC2-00-00-15 or later)
A10: 100K Higgs to tau tau THIS SET IS DONE.  NOTE THAT TAG GeneratorOptionsDC2-00-00-20 or later MUST BE USED)
A11: 50K DC1 susy. This is data set 2315 from DC1. Used primarily for G4 validation.  Old generated events need conversion to force K and Lambda to be stable.  THIS SET IS DONE


Class B:

B1 1 M jets (pt>180) (bias= 0.001)     THIS SET IS DONE
B2: 0.2 M gamma+jet (p_t>20) (bias=0.00125) THIS SET IS DONE. TEST FILE HAS BEEN VALIDATED
B3 : 0.25M bb->B->(mu6mu6)   THIS SET IS DONE
B4: 1M jets with (p_T>17),  prefiltering to provide sample of e/gamma fakes. bias depends on Filter. THIS SET IS DONE, The filter passes 5%: therefore 20M events need to be generated. The generator threshold is lowered to 15 GeV so the filter is less efficient than DC1. TEST FILE HAS BEEN VALIDATED
B5: 50K gamma_jet prefiltering to provide sample of gamma- gamma fakes. bias depends on Filter.THIS SET IS DONE, The filter passes 6%: therefore almost 1M events need to be generated. The generator threshold is lowered to 15 GeV so the filter is less efficient than DC1. TEST FILE HAS BEEN VALIDATED



Miscellaneous Higgs samples (these have smaller cross sections than class A and therefore have a much larger bias in the mixed sample.

H1: 40K  Higgs to 4 leptons. Higgs mass 130 GeV. Pythia. Events will be filtered to give all leptons with p_T>5 GeV and |eta| < 2.7. The filter is 61% efficient. 70K events will be generated.
THIS SET IS DONE

H2 40K  Higgs to 4 leptons. Higgs mass 180 GeV. Pythia. Events will be filtered to give all leptons with p_T>5 GeV and |eta| < 2.7. The filter is 72% efficient. 60K events will be generated. THIS SET IS DONE

H3 15K  Higgs to gamma+gamma. Higgs mass 120 GeV. Pythia. Events will be filtered to give photons  with p_T>20 GeV and |eta| < 2.7. The filter is 74% efficient. 25K events will be generated.  THIS SET IS DONE

H4 15K  Higgs to WW. Both W decays to e or mu. Vector boson fusion process. Higgs mass 170 GeV. Pythia. The filter passes 72% of the events. 25K will be generated.THIS SET IS DONE

H5: 15K  Higgs to WW. One W decays to e or mu, the other to hadrons  Vector boson fusion process. Higgs mass 170 GeV. Pythia. Events will be filtered so that lepton  passes trigger. The filter passes 44%.  50K will be generated. THIS SET IS DONE

H6: 15K  Higgs to tau tau. Both taus decay to e or mu. Vector boson fusion process. Higgs mass 115 GeV. Pythia. Events will be filtered so that leptons  pass trigger. Events will be filtered so that leptons pass trigger. The filter passes 9%.  200K will be generated.THIS SET IS DONE

H7: 15K  Higgs to tau tau. One tau decays to e or mu, the other to hadrons . Vector boson fusion process. Higgs mass 115 GeV. Pythia. Events will be filtered so that lepton  passes trigger. The filter passes 48%.  35K will be generated.THIS SET IS DONE (THERE IS A TYPO IN THE OPTIONS IN RELEASE 8.0.4 USE 8.0.5 OR or 8.0.4 with GeneratorOptionsDC2-00-00-11 or later)

H8: 15K MSSM Higgs producing bbA final state with A decaying to mu mu.  A mass 300 GeV Pythia. 
Events will be filtered so that leptons  pass trigger. The filter passes 89%. therefore no filter will be applied in this case NOTE THAT TAG GeneratorOptionsDC2-00-00-20 or later MUST BE USED)

H9: 15K MSSM Higgs producing bbA final state with A decaying to b b, A mass 500 GeV  Pythia.  Events will be filtered so that  there are two b's with |eta|< 2.5 and at least 4 jets with pt>20 GeV. There is no generator level filter for b's. Therefore these events are not filtered as the jet filter is very efficient.   NOTE THAT TAG GeneratorOptionsDC2-00-00-20 or later MUST BE USED)

Pile up

Pythia will be used for the min-bias pile up events. Herwig/Jimmy cannot be tuned properly.

M1 : 500K min bias events with the atlas tunings THIS SET IS DONE



Jet and single particle Calibration Samples



A prioritized list is being drawn up.
See here for the egamma
See here for the jets and pions