Comparable H0 and ttbar semileptonic datasets

CMS
1

I’ve been looking for more recent datasets similar to those used in this paper: https://arxiv.org/pdf/1402.4735.pdf

I found several ttbar->semileptonic decay samples and I also found, for example, H0->2L2Nu but I’m not sure what to look for to find a comparable theoretical H0-> semileptonic sample with H+/- and h0 decay mode. Miniaod format would be ideal for my objectives.

Does such a sample exist? If so, any help locating such a sample would be greatly appreciated.

2

Hi Eric,

This is a tough one – my first guess is that we don’t have this exact analog.

The existing BSM Higgs samples can be found here, subject to limitations of our categorization scripts… There are some samples like “ATo…” or “Higgs0PMTo…” that might point in the right direction (BSM neutral higgs to start, with various decays), but I don’t see any that clearly indicate a heavy neutral decaying to Hplus or Hminus.

If you’re able to find a CMS paper that studies this model or a similar one we could identify the samples used and see if any are (or will soon be) on the Open Data Portal.

Similarly, if you have the generator information for this process we can help guide you through the process of making your own MiniAOD.

Regards,
Julie Hogan

3

Thanks for the reply Julie! I haven’t really worked with pythia before but I believe that the decay process could be broken down into two sets of pythia string instructions based on the pdgid’s listed in the cern twiki.

String 1: gg → H0 → W+/- H-/+ → W+/- W-/+ h0 → W+/- W-/+ b bar → jj b bar l- nu

pythia.readString(“HardQCD:gg2gg = on”)
pythia.readString(“HiggsSM:gg2H = on”)

pythia.readString(“35:onMode = off”)
pythia.readString(“35:onIfMatch = 24 -37”)

pythia.readString(“-35:onMode = off”)
pythia.readString(“-35:onIfMatch = -24 37”)

pythia.readString(“-37:onMode = off”)
pythia.readString(“-37:onIfMatch = -24 25”)

pythia.readString(“37:onMode = off”)
pythia.readString(“37:onIfMatch = 24 25”)

pythia.readString(“25:onMode = off”)
pythia.readString(“25:onIfMatch = 5 -5”)

pythia.readString(“24:onMode = off”)
pythia.readString(“24:onIfAny = 11 12 13 14 15 16”)

pythia.readString(“-24:onMode = off”)
pythia.readString(“-24:onIfMatch = 2 -1”)
pythia.readString(“-24:onIfMatch = 4 -3”)

String 2: gg → H0 → W+/- H-/+ → W+/- W-/+ h0 → W+/- W-/+ b bar → jj b bar l+ nu

pythia.readString(“HardQCD:gg2gg = on”)
pythia.readString(“HiggsSM:gg2H = on”)

pythia.readString(“35:onMode = off”)
pythia.readString(“35:onIfMatch = 24 -37”)

pythia.readString(“-35:onMode = off”)
pythia.readString(“-35:onIfMatch = -24 37”)

pythia.readString(“-37:onMode = off”)
pythia.readString(“-37:onIfMatch = -24 25”)

pythia.readString(“37:onMode = off”)
pythia.readString(“37:onIfMatch = 24 25”)

pythia.readString(“25:onMode = off”)
pythia.readString(“25:onIfMatch = 5 -5”)

pythia.readString(“-24:onMode = off”)
pythia.readString(“-24:onIfAny = -11 -12 -13 -14 -15 -16”)

pythia.readString(“24:onMode = off”)
pythia.readString(“24:onIfMatch = -2 1”)
pythia.readString(“24:onIfMatch = -4 3”)

And then something similar for ttbar->semi-leptonic.

I’m not entirely sure how to actually utilize these strings in the cms-sw pythia generation scripts or how to go from there to miniaod. Any insights or links to resources would be much appreciated.

Best,
Eric Reinhardt

4

With some help from my group I found a slight mistake and got to the point where I have two generator scripts.

Not sure of the next steps from here to get to miniaod.

5

Hi Eric,

Sorry for the delay, I had a week of vacation.

A few thoughts:

  1. I think for semi-leptonic ttbar you should not need to generate anything. Assuming you are looking for SM production the existing samples should be fine.

  2. I assume you’re somewhat confident that Pythia knows how to do this BSM Higgs? We can always use Madgraph, etc, if needed, but that requires a BSM model file from theorists.

Here’s the big info dump for how to plug in your Pythia configuration:

  • Here is a page of general information on event production: opendata.cern.ch/docs/cms-guide-event-production
  • Here is a step-by-step of how to generate some 2012 AOD, which is conceptually very similar to what you would want for 2015: github.com/cms-opendata-analyses/EventProductionExamplesTool/tree/2012/MCQCDProductionMLTrackInfo
  • Here is an example of a 2015 MiniAOD sample that was generated with only Pythia, as you’re proposing: opendata.cern.ch/record/18358
    • At the bottom of that page there are 3 “steps” that each have a “Configuration file”.
    • Start by looking at the SIM step. In the SIM configuration file you’ll find the Pythia block that you can replace. (You can also consider changing things like file names, annotations, etc, to be more sensible for you)
    • This could be run with “cmsRun thisConfig.py”
    • For the HLT, RECO, and MINIAODSIM steps, the config files are only examples. The 5th line of each file gives the command-line options for cmsDriver.py. I would run cmsDriver.py using these command line options, but swapping the input and output file names to the local files you are producing, like you will see in the 2012 example.

That’s a lot! Let me know how it goes and where things get stuck.

Julie

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