Add HHModelPinvVHH model.

This PR adds a variant of the HH model with support for the VHH process. The overall rate is now composed of r * [GGF + VBF + VHH] with a corresponding rate parameter r_vhh to control the standalone rate of VHH. The additions to the model are mostly a copy of what is already there for VBF with a few things left to do:

• Verify that the VHH formula is indeed similar to VBF. Right now, it's really just a plain copy.
• Update the cross section values of the VHH samples.
• Check if the label naming scheme is applicable. Maybe it's worth to rename C3 to kl to be fully consistent with the GGF and VBF samples.
• Update tasks and plots for additional r_vhh parameter.

When merged, the new model should perhaps live next to the existing one to avoid interference with the current GGF+VBF combination efforts. In the long term, this combined model might be favorable though.

@lowang @capalmer @lcadamur

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• dfce6efe - Adapt tasks and plots for additional r_vhh parameter.

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marked the checklist item Update tasks and plots for additional r_vhh parameter. as completed

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• 0863a484 - update xsecs for VHH process and follow naming conventions

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marked the checklist item Verify that the VHH formula is indeed similar to VBF. Right now, it's really just a plain copy. as completed

marked the checklist item Update the cross section values of the VHH samples. as completed

marked the checklist item Check if the label naming scheme is applicable. Maybe it's worth to rename C3 to kl to be fully consistent with the GGF and VBF samples. as completed

Looks like this converged quite quickly.

@lowang Can you try to create a limit scan with this branch? E.g.

law run PlotUpperLimits \
  --version dev1_model \
  --hh-model HHModelPinvVHH.model_default \
  --datacards <your_cards_here> \
  --pois r_vhh \
  --scan-parameters C2V,-10,10,21 \
  --show-parameters kl,CV \
  --workers <cores>

If you are on a Mac and have iterm with imgcat enabled, you can also add --view-cmd imgcat which will show the plot in the terminal after the tasks are done.

Hi Marcel,

I run the command on our test datacard and it seems running smoothly without errors.

limits__poi_r_vhh__scan_C2V_-10.0_10.0_n21__params_r1.0_r_qqhh1.0_r_gghh1.0_kl1.0_kt1.0_CV1.0.pdf

Fyi, I ran a quick comparison with the bbzz4l datacards (which do only depend on r_gghh) to check if the results remain the same. So indeed, datacards without the samples that are matched by the model and assigned to the respective r_* parameter are still evaluated correctly (the curves are identical).

model_check.pdf

@lowang Good to hear!

Did you disable the uncertainty band in your plot?

You can also add --y-log for better visualization.

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• 530cffee - Fix multi model tasks.

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Yeah it seems the r is too large that y-axis overshadowed the uncertainty band. limits__poi_r_vhh__scan_C2V_-10.0_10.0_n21__params_r1.0_r_qqhh1.0_r_gghh1.0_kl1.0_kt1.0_CV1.0__log.pdf

Ah that rings a bell. The smooth graph area interpolation fails in ROOT when the point errors are outside the canvas. You can set --y-max to e.g. 1e7 to verify that the bands are at least extracted correctly.

No, I would rather think that combine did not save the uncertainty values in the output files. Can you send me the output of the MergeUpperLimits task (a single npz file) ?

I checked your output,

and combine can't estimate the other quantiles (see attachment), so I think we can leave it like that for now.

@lcadamur Would you mind having a look at the model file? The VHH-related parts are really just plain copies of the VBF code. Thank you!

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• e3ab98f8 - Update comments in model.

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• e3ab98f8...3a2b1334 - 18 commits from branch master
• 03f17eae - Merge branch 'master' into feature/vhh.

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Hi, thanks a lot for this! By checking the code committed all seems good to me. Do you maybe have a workspace that is built after text2workspace to directly cross-check how the scalings are implemented in RooFit workspace?

Thanks for checking!

Here is the bbzz4l workspace creating with this model: workspace_vhh_bbzz4l.root

Thanks! @lowang one can just open the workspace and do w->Print() to inspect the functions that it contains. In this way one can check

• that all the scalings exist
• that the expressions are correct
• that the names are univocal
• that the scalings affect the right processes

I will also have a look at the workspace

Great to know, thank you very much!

Hi again, I might have missed it from the discussion above, but this workspace does not contain any VHH nor VBF signal, correct? I see inside the scaling functions but they are not attached to any process (so one cannot verify the last point above).

Right, the workspace I uploaded does not have the any VHH process attached as I only verified that the existing results remain stable.

OK makes sense then, thanks. Once there is a card with VHH sample I think it will be good to verify that the association is done correctly and that it is picked up by the additional scalings of the branching ratios since these are applied on top of the former and "on demand".

@lowang Did you rename the signal processes in your datacard so that they are picked up by the model? There is a block printed after the workspace is written (in the done() method) which should give you some insights.

Yeah the above attached workspace.root file is produced using the VHH sample which has corresponding processes named following the naming convention in my test datacard.

I added the output of w.Print() here for future reference: workspace.txt

The f_vhhscale_sample_* formulae look good to me.

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• 9ee59d6f - Merge branch 'master' into feature/vhh.

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resolved all threads

marked this merge request as ready

If there are no objections, we could merge this one so that @lowang and @capalmer can go ahead.

@lcadamur @agbet @defilip @acarvalh

No objection from my side. It doesn't look like this commit will interfere with the current workflow of the ongoing analyses. I trust you have tested sufficiently.

ok for me

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• 4cb1a1ba - Merge branch 'master' into feature/vhh.

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are we ready to merge?

resolved all threads

mentioned in commit f5d09e89

merged

Yay! Thanks!