Implementation of Dark Bremsstrahlung Custom Process #38329

revering · 2022-06-10T22:26:25Z

PR description:

Implemented physics for dark bremsstrahlung and cross section biasing into SimG4Core/CustomPhysics. Overview of implementation method and motivation available from presentation to SIM group: https://indico.cern.ch/event/1162548/contributions/4882745/attachments/2447856/4194591/Revering_DarkBrem_Sim_22_5_20.pdf

Dark Bremsstrahlung is implemented as an optional process in the CustomPhysics module, and an example _cfi file with brief instructions has been added to SimG4Core/CustomPhysics/DarkBrem_SIM_cfi.py. The new process should have no impact on event generation that does not explicitly call it and include the necessary watcher plugin. A location dependent cross section biasing class is also implemented, and as with the process itself is only instantiated through the DBremWatcher plugin.

PR validation:

A small sample of events was generated locally in CMSSW_12_5_X_2022-06-09-1100 to verify that the cross section biasing was taking place in the correct areas of the detector and was producing events at a reasonable rate. Large samples have been generated in CMSSW_10_2_6 to validate the process itself and verify that the cross section calculations are functional for both the total cross section and the expected kinematics. The kinematic calculations do not have any reliance on external cmssw modules, so the behavior should be identical between the two versions.

cmsbuild · 2022-06-10T22:33:09Z

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-38329/30508

This PR adds an extra 28KB to repository

cmsbuild · 2022-06-10T22:33:33Z

A new Pull Request was created by @revering for master.

It involves the following packages:

SimG4Core/CustomPhysics (simulation)

@cmsbuild, @civanch, @mdhildreth can you please review it and eventually sign? Thanks.
@makortel, @cvuosalo, @rovere, @bsunanda, @fabiocos, @slomeo this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

civanch · 2022-06-11T18:46:05Z

SimG4Core/CustomPhysics/src/APrimePhysics.cc

+  G4ParticleDefinition* muonplus = G4MuonPlus::MuonPlusDefinition();
+  G4ProcessManager* pmplus = muonplus->GetProcessManager();
+  G4ProcessManager* pmminus = muonminus->GetProcessManager();
+  pmplus->AddProcess(new G4muDarkBremsstrahlung(mgfile), -1, 1, 1);


@revering , I would advice (-1, 1, 1) substitute by (-1, 6, 6)

civanch · 2022-06-11T18:47:16Z

@revering , sorry, I was not checking your proposal earlier. Now several comments. First of all technical:

all source files should be *.cc
all lines with std::cout should be removed or substituted by edm::LogVerbatim
edm::LogInfo better to substitute by edm::LogVerbatim
if a header file is not used in the header it should be removed or moved to the source
#include "G4PhysicalConstants.hh" and #include "G4SystemOfUnits.hh" are allowed only in source files, not in headers.
if you use "delete" keyword in a header the method should be public
Watchers should be in src not inside plugin

Now more complicate comments, I am not 100% sure what is the best solution.

If you implement some extra product in SimProducer, then you need to take into account that watchers and producers are MT only for Run3 in recent CMSSW releases, for Run-2 it will work only in 1 thread runs. If for your analysis the producer is needed strongly it is possible to implement extra products in this way, but you should take care to submit 1 thread job for Run-2 production.
biasing approach is relatively new for Geant4 . In 10.4 and 10.7 the code may be different, I am not sure if it is MT safe in previous version. Are you sure that it is the only solution you may use? I would recommend to use simplest approach - use factor, defined in python configuration file as the particle mass. Multiply cross section by this factor - it is a transparent method.
I do not fill numbers, what is the spectra of dark matter bremsstrahlung?
May it be that this physics does not need G4VEnergyLossProcess interface by G4VEmProcess interface. The energy loss is used for simulation of ionisation - energy transfer to low-energy electrons. Here we have dark

cmsbuild · 2022-06-15T19:52:46Z

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-38329/30576

This PR adds an extra 28KB to repository
Found files with invalid states:
- SimG4Core/CustomPhysics/src/DarkBremXsecBiasingOperator.cxx:
  - Added: 904e102
  - Deleted: c823e3a
- SimG4Core/CustomPhysics/src/XsecBiasingOperator.cxx:
  - Added: 904e102
  - Deleted: c823e3a
- SimG4Core/CustomPhysics/plugins/DBremWatcher.cc:
  - Added: 904e102
  - Deleted: 70e0d61

Code check has found code style and quality issues which could be resolved by applying following patch(s)

code-format:
https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-38329/30576/code-format.patch
e.g. curl -k https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-38329/30576/code-format.patch | patch -p1
You can also run scram build code-format to apply code format directly

cmsbuild · 2022-06-15T20:08:47Z

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-38329/30577

This PR adds an extra 28KB to repository
Found files with invalid states:
- SimG4Core/CustomPhysics/src/DarkBremXsecBiasingOperator.cxx:
  - Added: 904e102
  - Deleted: c823e3a
- SimG4Core/CustomPhysics/src/XsecBiasingOperator.cxx:
  - Added: 904e102
  - Deleted: c823e3a
- SimG4Core/CustomPhysics/plugins/DBremWatcher.cc:
  - Added: 904e102
  - Deleted: 70e0d61

cmsbuild · 2022-06-15T20:09:11Z

Pull request #38329 was updated. @cmsbuild, @civanch, @mdhildreth can you please check and sign again.

revering · 2022-06-15T20:16:22Z

@civanch Thank you for the comments! I've modified the implementation to hopefully fix the technical issues detailed in notes 1-7, and changed the process to inherit from G4VEmProcess instead of G4VEnergyLossProcess as suggested in note 4. I produced a small sample of 100 events, and the process still occurs around the expected rates.

The main issue remaining is the question of the biasing and multi-threading. While we certainly could implement a global multiplicative factor as you suggest, we would need to re-implement the location dependence and would lose the track weights produced by the biasing operator, limiting the bias factors we could apply without producing non-physical modification to the event locations. I'm not really sure how we could put the location dependence in - my best idea for now would be to modify SampleSecondaries() in the model so that it gets the detector location when an interaction is proposed, and then chooses whether or not to simulate the interaction depending on a given list of allowed detector regions.
I would really prefer to use the existing bias method if possible - we need the sim-level information about the process that is produced with DBremWatcher for our analysis, so we're already limited to single-threaded running in run 2 generation and we've seen that the biasing works alright there. Is there some kind of test we could run to see if the biasing works in multithreaded generation for run 3?

In addition to the concerns about multithreading and the bias factors, I'm worried about the process disabling that we do to limit the interaction and multithreading. When SampleSecondaries() is called in G4muDarkBremsstrahlungModel, it gets the process manager and sets the process activation to false. At the start of the next event, DBremWatcher then sets it back to true. Do you know if this will work with multithreading? From what I can tell the processManager is thread-local, but I'm not sure if the activation tables they use are a shared variable or not. If they are shared, then one thread producing a brem might turn off the process for the others, or a thread starting an event could turn it on for a thread that needs it disabled.

civanch · 2022-06-16T18:26:04Z

please test

cmsbuild · 2022-06-16T22:19:26Z

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-f56f2d/25571/summary.html
COMMIT: d117c9b
CMSSW: CMSSW_12_5_X_2022-06-16-1100/el8_amd64_gcc10
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/38329/25571/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

No significant changes to the logs found
Reco comparison results: 0 differences found in the comparisons
DQMHistoTests: Total files compared: 50
DQMHistoTests: Total histograms compared: 3659074
DQMHistoTests: Total failures: 2
DQMHistoTests: Total nulls: 0
DQMHistoTests: Total successes: 3659050
DQMHistoTests: Total skipped: 22
DQMHistoTests: Total Missing objects: 0
DQMHistoSizes: Histogram memory added: 0.0 KiB( 49 files compared)
Checked 208 log files, 45 edm output root files, 50 DQM output files
TriggerResults: no differences found

cmsbuild · 2022-07-25T16:25:40Z

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-38329/31264

This PR adds an extra 24KB to repository

cmsbuild · 2022-07-25T16:26:06Z

Pull request #38329 was updated. @cmsbuild, @civanch, @mdhildreth can you please check and sign again.

perrotta · 2022-07-25T16:39:09Z

please test

cmsbuild · 2022-07-25T20:26:02Z

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-f56f2d/26448/summary.html
COMMIT: d44f06d
CMSSW: CMSSW_12_5_X_2022-07-25-1100/el8_amd64_gcc10
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/38329/26448/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

No significant changes to the logs found
Reco comparison results: 0 differences found in the comparisons
DQMHistoTests: Total files compared: 51
DQMHistoTests: Total histograms compared: 3667670
DQMHistoTests: Total failures: 2
DQMHistoTests: Total nulls: 0
DQMHistoTests: Total successes: 3667646
DQMHistoTests: Total skipped: 22
DQMHistoTests: Total Missing objects: 0
DQMHistoSizes: Histogram memory added: 0.0 KiB( 50 files compared)
Checked 210 log files, 47 edm output root files, 51 DQM output files
TriggerResults: no differences found

civanch · 2022-07-26T05:03:32Z

+1

cmsbuild · 2022-07-26T05:03:57Z

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy, @rappoccio (and backports should be raised in the release meeting by the corresponding L2)

civanch · 2022-07-26T05:10:18Z

@revering , let us make a backport to 12_4 (it may be run3 MC production release). This backport is straightforward - the same files as in 12_5 may be committed.

For 10_6 (Run2 MC production) the backport should be done with care, because modified classes may be different from those of 12_5. It is not possible blindly substitute files but it is needed check classes one by one.

perrotta · 2022-07-26T05:29:27Z

+1

forthommel · 2022-07-26T07:48:34Z

SimG4Core/CustomPhysics/interface/APrimePhysics.h

@@ -0,0 +1,40 @@
+#ifndef SIMAPPLICATION_APRIMEPHYSICS_H_
+#define SIMAPPLICATION_APRIMEPHYSICS_H 1_


Possible multiple include here (SIMAPPLICATION_APRIMEPHYSICS_H_ vs. SIMAPPLICATION_APRIMEPHYSICS_H)

Good catch, thank you @forthommel !
I submitted a fix in #38862

aandvalenzuela · 2022-08-02T15:35:13Z

Hello,

It seems this PR broke G4VECGEOM IBs #38935.
Could you please have a look at it?

Many thanks,
Andrea.

makortel · 2022-08-02T15:36:40Z

SimG4Core/CustomPhysics/interface/G4muDarkBremsstrahlung.h

+
+  G4bool IsApplicable(const G4ParticleDefinition& p) override;
+
+  void PrintInfo() override;


As far as I can tell, this member function could be removed (and that would fix the G4VECGEOM IB).

I've made a new PR #38949 with PrintInfo() removed to resolve the issue.

cmsbuild added this to the CMSSW_12_5_X milestone Jun 10, 2022

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civanch reviewed Jun 11, 2022

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cmsbuild merged commit d274e60 into cms-sw:master Jul 26, 2022

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perrotta mentioned this pull request Jul 26, 2022

Fix header guard in APrimePhysics.h #38862

Merged

makortel mentioned this pull request Jul 27, 2022

Add missing dependencies to SimG4Core/CustomPhysics/BuildFile.xml #38874

Merged

This was referenced Jul 28, 2022

Implemented optional Dark Bremsstrahlung process into custom physics #38888

Merged

Dark Bremsstrahlung backport to 10_6_X #38901

Merged

aandvalenzuela mentioned this pull request Aug 2, 2022

[G4VECGEOM_X] IB reports compiler errors for both gcc10 and gcc11. #38935

Closed

makortel reviewed Aug 2, 2022

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makortel mentioned this pull request Aug 8, 2022

Moved DBremWatcher to plugins directory #38994

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Implementation of Dark Bremsstrahlung Custom Process #38329

Implementation of Dark Bremsstrahlung Custom Process #38329

revering commented Jun 10, 2022

cmsbuild commented Jun 10, 2022

cmsbuild commented Jun 10, 2022

civanch Jun 11, 2022

civanch commented Jun 11, 2022

cmsbuild commented Jun 15, 2022

cmsbuild commented Jun 15, 2022

cmsbuild commented Jun 15, 2022

revering commented Jun 15, 2022

civanch commented Jun 16, 2022

cmsbuild commented Jun 16, 2022

cmsbuild commented Jul 25, 2022

cmsbuild commented Jul 25, 2022

perrotta commented Jul 25, 2022

cmsbuild commented Jul 25, 2022

civanch commented Jul 26, 2022

cmsbuild commented Jul 26, 2022

civanch commented Jul 26, 2022

perrotta commented Jul 26, 2022

forthommel Jul 26, 2022

perrotta Jul 26, 2022

aandvalenzuela commented Aug 2, 2022

makortel Aug 2, 2022

revering Aug 2, 2022

		@@ -0,0 +1,40 @@
		#ifndef SIMAPPLICATION_APRIMEPHYSICS_H_
		#define SIMAPPLICATION_APRIMEPHYSICS_H 1_


		G4bool IsApplicable(const G4ParticleDefinition& p) override;

		void PrintInfo() override;

Implementation of Dark Bremsstrahlung Custom Process #38329

Implementation of Dark Bremsstrahlung Custom Process #38329

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revering commented Jun 10, 2022

PR description:

PR validation:

cmsbuild commented Jun 10, 2022

cmsbuild commented Jun 10, 2022

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civanch commented Jun 11, 2022

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revering commented Jun 15, 2022

civanch commented Jun 16, 2022

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Comparison Summary

cmsbuild commented Jul 25, 2022

cmsbuild commented Jul 25, 2022

perrotta commented Jul 25, 2022

cmsbuild commented Jul 25, 2022

Comparison Summary

civanch commented Jul 26, 2022

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