Delphes in expert mode

Hi Shubhani

There is not much to do with delphes through expert mode. You only need to run delphes and get the ROOT output in normal mode and then you just need to write your own analysis in expert mode to read the delphes output which is automatically done. You just need to give the path of your root file. So here is a summary;

./bin/ma5 -R
set main.fastsim.package = delphes
set main.fastsim.detector = cms
import my_hepmc_file
submit delphes_run

it will ask you if you like to modify the default card, you can do as you please and the rest is handled via ma5.

After this is done, you can prepare your expert-mode analysis, compile and just run it with the ROOT output.

Cheers

—
Jack Y. Araz

> On Oct 23, 2020, at 9:01 AM, Shubhani Jain <email address hidden> wrote:
>
> New question #693596 on MadAnalysis 5:
> https://answers.launchpad.net/madanalysis5/+question/693596
>
> Hi
>
> Can you please guide me as to how to get Delphes running in MA5 expert mode properly as for our analysis we use Variable-R algorithm from Fastjet contrib to cluster our particles into jets.
>
> Thanks.
>
> Regards
> Shubhani
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

Hi Jack

Thanks for the prompt answer. Is there any way to edit Delphes card to get rid of jet clustering part and do that ourselves intead?

Regards
Shubhani

Hi Shubhani

That might be a bit dangerous since delphes needs the clustered jets to apply detector effects on them. But you can recluster it when you get the root file. This will require a little hack to use FastJet in the analysis itself. multi-jet clustering is under development at the moment, so you will need to modify the Makefile and add the FastJet library flags there so that you can use it through your expert-mode folder. Please don’t forget to add contrib flags as well if you wish to use a particular one.

Another method is using the SFS module in expert-mode instead of delphes, which will give you a bit more flexibility. With this option you will not need a ROOT file to work on, you can directly run everything on HEPMC file and SFS module will apply detector effects on the fly and you will have access to all detector effects through your analysis folder.

Cheers

—
Jack Y. Araz

> On Oct 23, 2020, at 10:31 AM, Shubhani Jain <email address hidden> wrote:
>
> Question #693596 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/693596
>
> Shubhani Jain posted a new comment:
> Hi Jack
>
> Thanks for the prompt answer. Is there any way to edit Delphes card to
> get rid of jet clustering part and do that ourselves intead?
>
> Regards
> Shubhani
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

Hi Jack

We are actually using fastjet in the analysis already. In particular, we use Variable-R clustering algorithm rather than anti-kt or C/A. We had to manually download the package for it from fastjet contrib to use in the analysis, so is there a way to incorporate that in delphes default card?

Regards
Shubhani

Hi Shubhani,

In this case, you may want to consider instead our internal SFS fastsim, that may be more appropriate for such a goal (see 2006.09387 for more information).

Cheers,

Benjamin

> On 23 Oct 2020, at 13:30 , Shubhani Jain <email address hidden> wrote:
>
> Question #693596 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/693596
>
> Shubhani Jain posted a new comment:
> Hi Jack
>
> We are actually using fastjet in the analysis already. In particular, we
> use Variable-R clustering algorithm rather than anti-kt or C/A. We had
> to manually download the package for it from fastjet contrib to use in
> the analysis, so is there a way to incorporate that in delphes default
> card?
>
> Regards
> Shubhani
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

Hi

Thanks for the answer. Just one more naive question is it possible to implement delphes in expert mode the same way as fastjet described here:

"FastJet in the analysis itself. multi-jet clustering is under development at the moment, so you will need to modify the Makefile and add the FastJet library flags there so that you can use it through your expert-mode folder. Please don’t forget to add contrib flags as well if you wish to use a particular one."

Regards
Shubhani

Hi Shubhani

From delphes you have access to substructure of the jets. So you will need to recluster them and use that as your new jet. Note that if you want to use your clustering method in delphes you will need to modify the delphes modules which is not related to Ma5. Delphes and Ma5 are independent programs, Ma5 running delphes and reading the output coming from delphes. Rest can be done either at the analysis level or as I said by modifying delphes’ modules.

Cheers

—
Jack Y. Araz

> On Oct 23, 2020, at 2:50 PM, Shubhani Jain <email address hidden> wrote:
>
> Question #693596 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/693596
>
> Shubhani Jain posted a new comment:
> Hi
>
> Thanks for the answer. Just one more naive question is it possible to
> implement delphes in expert mode the same way as fastjet described here:
>
> "FastJet in the analysis itself. multi-jet clustering is under
> development at the moment, so you will need to modify the Makefile and
> add the FastJet library flags there so that you can use it through your
> expert-mode folder. Please don’t forget to add contrib flags as well if
> you wish to use a particular one."
>
> Regards
> Shubhani
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

Hi Jack

That makes sense, thanks for the answers.

Regards
Shubhani