Can't access filled N-subJettiness variables

[Owen Colegrove]

Hi all,

I am getting familiarized with Delphes and I have found what seems to be an error of sorts. I am using the Delphes 100TeV fastsim-002 MC. These MC datasets are distributed as root files filled w/ Delphes objects.

I have had no issues whatsoever getting started, except that I cannot access subjet information. The vector corresponding to N-subJettiness ("Tau" under the jet class) is clearly filled when I view in the TBrowser. However, I cannot access this information through what should be acceptable methods.

Instantiating a Jet as
Jet* j = (Jet*) branchJet->At(i);

I can access the jet pt,eta, and phi. However, the tau1,tau2,...tau5 variables all return zero when accessed. I also tried to directly access the Tau vector by calling:

j->Tau[0]

But this returns the error

Error: Failed to evaluate j->Tau[0]

I know this is the correct call as I can call
j->FracPt[0]

without issue.

What is going on here? How might I access the tau variables?

[Michele Selvaggi]

Hi,

I cannot reproduce your error with Delphes-3.3.0. Can you point me to the sample that gives you trouble, and please indicate which delphes card and delphes version was used to produce it please?

Michele

[Owen Colegrove]

Hi,

I am accessing the fast sim samples described here:
​http://atlaswww.hep.anl.gov/hepsim/info.php?item=57

(I believe the datacard is here)
​http://raw.stash2.ci-connect.net/@HepSim/events/pp/100tev/ttbar_pt2500_mg5/rfast002/info.txt

with the corresponding download link located:
​http://atlaswww.hep.anl.gov/hepsim/show.php?item=57&reco=rfast002

If it helps, I am using Delphes 3.20. Could this be a source of the error?

[Michele Selvaggi]

Hi,

yes this might be related to the fact that you are using the Delphes library from 3.2.0 while the sample was produced with 3.3.0.

Please try the following:

1) Download and install Delphes3.3.0
2) Modify examples/Example2.C by adding at line 130 the following:

cout<<jet[0]->Tau[0]<<endl;

3) Run the script:

root -b -q examples/Example2.C'("tev100_mg5_ttbar_pt2500__00001.root")'

Let me know if this works,
Michele