photon in Delphes

[olivier]

reported here: ​https://answers.launchpad.net/mg5amcnlo/+question/254568

Hi everyone,

I was running MG5 2.1.2 to generate two photons and a pair b b~ as a final state. And then, doing the showering with Pythia and then the detector simulation with Delphes. The plots of the Pythia level are ok in that appear the expected photons, but at the Delphes level the photons disappear. I already try installing Delphes, Delphes 2 and Delphes 3 but without difference on the plots .

I run my model_UFO in other computer and Delphes work ok, so the problem apparently is with my Delphes.

Thanks in advance for any comment about this issue.

Cheers,

Daniel

[Michele Selvaggi]

Hi Daniel,

first, you really should not be using Delphes2, as it is not maintained anymore, and is known to produce strange results on photons.
I am not sure what "Delphes" means in MG command line, but I would suppose (and hope) this is the same as Delphes 3.

Besides, what is likely to happen is that you generate either very low pt photons (in which case they fail to pass the efficiency module)
or highly collinear to b's, (in which case they fail to pass isolation criteria).

Now, if you really are interested in such photons, you will have to relax the isolation criteria, and remove the UniqueObjectFinder module
from the sequence (otherwise you all jets that sufficiently close to photons will be vetoed).

Please check that this is really what you want, and in case I can send you modified version of the card that does this.

Cheers,
Michele

[Daniel]

Hi Michele,

I'm working with Delphes 3, but this does not work ok in my computer. In other computer Delphes work ok and show the graphs that I hope... so the problem I guess is the Delphes itself. In my computer Delphes just not generate any graph as well as not generate the .lhco file. I Try with differents versions of MG5 with the same unfortunate result. On the other hand, I have the root packages ok as well as the other like MadAnalysis that works with pythia and pgs in a correct way.

Thanks for any suggestion.

Daniel

[Michele Selvaggi]

Hi Daniel,

could you try to run Delphes in a standalone mode, I mean by taking the MG output and supplying it manually to Delphes.

You can find relevant instructions here, to download and install Delphes:

https://cp3.irmp.ucl.ac.be/projects/delphes/wiki/WorkBook/QuickTour

Cheers,
Michele

[Daniel]

Hi Michele

I already did that, the .lhco file was generated but the plots remains without photons, that is, there are the #a plots but its like how the only photons in my model are the photons of the showering of pythia.

Thanks for any suggestion.

Daniel

[Michele Selvaggi]

Could you attach here a small event file after pythia (*.hep file created by MG+pythia) ?

[Daniel]

Hi,

The tag_1_pythia_events.hep.gz have ~200MB, and the limit is 25MB. Its this file?

[Michele Selvaggi]

Yes that is too big. You'll have to generate another smaller sample with ~1000 events.
Also, attach the banner please so I can see how the events were generated.

[Daniel]

Hi,

I attached the files. Thanks for the help.

Daniel

[Michele Selvaggi]

Hi Daniel,

I have checked the lhco files and they look fine (i.e. they contain photons).
Which "#a plots" are you referring to? If these are MadAnalysis plots we cannot help.

Besides, you can try to produce plots by using root macros. There are a couple of examples in the example directory of Delphes.

./DelphesSTDHEP examples/delphes_card_CMS.tcl test.root tag_1_pythia_events.hep
root -b -q examples/Example3.C'("test.root")'

Then,

root results.root
TBrowser t;

or

eog *.png

The Example3.C macro will produce some plots by default. If you want different/more plots, you can easily modify it yourself according to your needs.

Michele

[Daniel]

Hi Michele,

I attached here one of the plots that Delphes give me (#a). I have 2 photons as a final state and it do not reproduce that. Do you reproduce the same graph?

On the other hand, when run from the Deplhes directory the root its not found, but it apparently work ok...

** [################################################################] (100.00%)
** Reading root
** ERROR: can't open root

Thanks for the help and for any suggestions!

daniel

[Michele Selvaggi]

I don't know how you produced that plot so I can't reproduce it.
You should locate first where root is installed on your machine.
Then, say it is located in ~/root:

You can then type:

source ~/root/bin/thisroot.sh

which will make the root executable available from everywhere.

Then you can open the root file with root as explained above, in the TBrowser you can double click on "results.root", then "Delphes", then "Photon_size" (or "Photon", then "@size") and you can see that the photon multiplicity is mostly 2 as expected.

[Daniel]

Hi Michele,

I just produced that plot running Delphes when I generate events. On the other hand I follow your advise (source ~/root/bin/thisroot.sh) and compile root to verify that its ok, but remains the mistake, look like this:

daniel@daniel:~/Documents/MG5_aMC_v2_1_2/Delphes$ ./DelphesSTDHEP examples/delphes_card_CMS.tcl atotest.root tag_1_pythia_events.hep root -b -q examples/Example3.C'("atotest.root")'
** INFO: adding module        ParticlePropagator       ParticlePropagator       
** INFO: adding module        Efficiency               ChargedHadronTrackingEfficiency
** INFO: adding module        Efficiency               ElectronTrackingEfficiency
** INFO: adding module        Efficiency               MuonTrackingEfficiency   
** INFO: adding module        MomentumSmearing         ChargedHadronMomentumSmearing
** INFO: adding module        EnergySmearing           ElectronEnergySmearing   
** INFO: adding module        MomentumSmearing         MuonMomentumSmearing     
** INFO: adding module        Merger                   TrackMerger              
** INFO: adding module        Calorimeter              Calorimeter              
** INFO: adding module        Merger                   EFlowMerger              
** INFO: adding module        Efficiency               PhotonEfficiency         
** INFO: adding module        Isolation                PhotonIsolation          
** INFO: adding module        Efficiency               ElectronEfficiency       
** INFO: adding module        Isolation                ElectronIsolation        
** INFO: adding module        Efficiency               MuonEfficiency           
** INFO: adding module        Isolation                MuonIsolation            
** INFO: adding module        Merger                   MissingET                
** INFO: adding module        Merger                   ScalarHT                 
** INFO: adding module        FastJetFinder            GenJetFinder             
** INFO: adding module        FastJetFinder            FastJetFinder            
** INFO: adding module        EnergyScale              JetEnergyScale           
** INFO: adding module        BTagging                 BTagging                 
** INFO: adding module        TauTagging               TauTagging               
** INFO: adding module        UniqueObjectFinder       UniqueObjectFinder       
** INFO: adding module        TreeWriter               TreeWriter               
** INFO: initializing module  Delphes                  
** INFO: initializing module  ParticlePropagator       
** INFO: initializing module  ChargedHadronTrackingEfficiency
** INFO: initializing module  ElectronTrackingEfficiency
** INFO: initializing module  MuonTrackingEfficiency   
** INFO: initializing module  ChargedHadronMomentumSmearing
** INFO: initializing module  ElectronEnergySmearing   
** INFO: initializing module  MuonMomentumSmearing     
** INFO: initializing module  TrackMerger              
** INFO: initializing module  Calorimeter              
** INFO: initializing module  EFlowMerger              
** INFO: initializing module  PhotonEfficiency         
** INFO: initializing module  PhotonIsolation          
** INFO: initializing module  ElectronEfficiency       
** INFO: initializing module  ElectronIsolation        
** INFO: initializing module  MuonEfficiency           
** INFO: initializing module  MuonIsolation            
** INFO: initializing module  MissingET                
** INFO: initializing module  GenJetFinder             
#--------------------------------------------------------------------------
#                         FastJet release 3.0.6
#                 M. Cacciari, G.P. Salam and G. Soyez                  
#     A software package for jet finding and analysis at colliders      
#                           http://fastjet.fr                           
#	                                                                      
# Please cite EPJC72(2012)1896 [arXiv:1111.6097] if you use this package
# for scientific work and optionally PLB641(2006)57 [hep-ph/0512210].   
#                                                                       
# FastJet is provided without warranty under the terms of the GNU GPLv2.
# It uses T. Chan's closest pair algorithm, S. Fortune's Voronoi code
# and 3rd party plugin jet algorithms. See COPYING file for details.
#--------------------------------------------------------------------------
** INFO: initializing module  FastJetFinder            
** INFO: initializing module  JetEnergyScale           
** INFO: initializing module  BTagging                 
** INFO: initializing module  TauTagging               
** INFO: initializing module  UniqueObjectFinder       
** INFO: initializing module  ScalarHT                 
** INFO: initializing module  TreeWriter               
** Reading tag_1_pythia_events.hep
** [################################################################] (100.00%)
** Reading root
** ERROR: can't open root
daniel@daniel:~/Documents/MG5_aMC_v2_1_2/Delphes$ 

I guess that maybe some library is not right, or something like that. I also try to run again from MG5 as is usual but the plots remains without the correct quantities of photons as well as the pt of them are so small.

thanks for any help to solve this problem.

Daniel

[Michele Selvaggi]

You should type in two separate lines:

./DelphesSTDHEP examples/delphes_card_CMS.tcl atotest.root tag_1_pythia_events.hep

and then

root -b -q examples/Example3.C'("atotest.root")'

…

Note that you can also directly open the file "atotest.root" with root, and browse its content with TBrowser:

root atotest.root
TBrowser t;

Once the browser is open, you can double click in the browser on "results.root", then "Delphes", then "Photon_size" (or "Photon", then "@size") and you can see that the photon multiplicity is mostly 2 as expected.

Please read carefully the provided instructions before asking here. Also note that we can't help you with every bash/root related questions, as this is not the purpose of this ticketing system.

For root documentation:
​http://root.cern.ch/drupal/content/documentation
​http://root.cern.ch/root/html532/tutorials/

Michele

[Daniel]

Hi Michele,

So sorry for by the carelessness in the run!..., nevertheless, despite that now I follow step by step the instructions and Delphes effectively run without any error, my Delphes configuration apparently do not detect any photons, the @size is for me mostly 0.

Regards,

Daniel

[Michele Selvaggi]

Hi Daniel,

I am kind of lost I have to say...

Did you try downloading a standalone delphes version? (not the one inside MG)

https://cp3.irmp.ucl.ac.be/projects/delphes/wiki/WorkBook/QuickTour

Another thing you can try is whether you get the same result with ATLAS and CMS cards:

./DelphesSTDHEP examples/delphes_card_CMS.tcl outcms.root tag_1_pythia_events.hep
./DelphesSTDHEP examples/delphes_card_ATLAS.tcl outatlas.root tag_1_pythia_events.hep

Michele

[Daniel]

Hi Michael,

I finally found the solution to my problem, I am going to write here in a very summary form because can be useful for someone more. Reads as follows:

1) You must to give the path for the directories of linux: sudo gedit /etc/ld.so.conf.d/randomLibs.conf and type export LD_LIBRARY_PATH=/usr/local/lib and
after... export LD_LIBRARY_PATH. Logout and login, LD_LIBRARY_PATH will have been set permanently.

2)The installation of root is make in the independent way.

3) Delphes run ok but besides to run tap the following: ./configure and after :make clean, and after :make.

With that my Delphes run ok and reproduce the physics that I expect.

Thank you so much for the patience and help in the search of my problem.

Cheers,

Daniel Camargo