momentum precision in indirect detection

Bug #1834831 reported by Olivier Mattelaer
12
This bug affects 2 people
Affects Status Importance Assigned to Milestone
MadDM
New
Undecided
Chiara Arina

Bug Description

Hi,

I am using MadDM for studying DM indirect detection. In my model, there are 3 kinds of CP-even neutral Higgs bosons, and DM can annihilate into a pair of them, as well as other final states.

I was trying to generate gamma-ray spectrum with the 'precise' mode. I found that the gamma-ray spectrum can be successfully generated for mDM > 100 GeV. However, for mDM < 100 GeV, PYTHIA 8 failed to generate the spectrum. The error information in pythia8.log is as follows.

 -------- LHA initialization information ------------

  beam kind energy pdfgrp pdfset
     A 52 97.198 0 247000
     B 52 97.198 0 247000

  Event weighting strategy = -4

  Processes, with strategy-dependent cross section info
  number xsec (pb) xerr (pb) xmax (pb)
    1995 5.4686e+02 8.3103e-01 5.4686e+02

 -------- End LHA initialization information --------
mDM: 9.7198e+01 outdir: ./
 PYTHIA Error in Pythia::check: energy-momentum not conserved
 PYTHIA Error in Pythia::next: check of event revealed problems
 PYTHIA Abort from Pythia::next: parton+hadronLevel failed; giving up
 PYTHIA Warning in TauDecays::decay: unknown correlated tau production, assuming from unpolarized photon
Event generation aborted prematurely, owing to error!

 *------- PYTHIA Event and Cross Section Statistics -------------------------------------------------------------*
 | |
 | Subprocess Code | Number of events | sigma +- delta |
 | | Tried Selected Accepted | (estimated) (mb) |
 | | | |
 |-----------------------------------------------------------------------------------------------------------------|
 | | | |
 | Les Houches User Process(es) 9999 | 10 10 0 | 0.000e+00 0.000e+00 |
 | ... whereof user classification code 1995 | 10 10 0 | |
 | | | |
 | sum | 10 10 0 | 0.000e+00 0.000e+00 |
 | |
 *------- End PYTHIA Event and Cross Section Statistics ----------------------------------------------------------*

 *------- PYTHIA Error and Warning Messages Statistics ----------------------------------------------------------*
 | |
 | times message |
 | |
 | 10 Abort from Pythia::next: parton+hadronLevel failed; giving up |
 | 100 Error in Pythia::check: energy-momentum not conserved |
 | 100 Error in Pythia::next: check of event revealed problems |
 | 1 Error in SigmaTotal::calc: too low energy |
 | 1 Info from SLHAinterface::initSLHA: attempting to set properties |
 | 1 Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off |
 | 1 Info from SLHAinterface::initSLHA: importing DECAY tables |
 | 1 Info from SLHAinterface::initSLHA: importing MASS entries |
 | 2 Warning in SLHAinterface::initSLHA: ignoring DECAY tables |
 | 1 Warning in SLHAinterface::initSLHA: ignoring MASS entries |
 | 4 Warning in SLHAinterface::initSLHA: ignoring QNUMBERS |
 | 1 Warning in SLHAinterface::initSLHA: massless particle forced stable |
 | 1 Warning in SLHAinterface::initSLHA: using QNUMBERS for id codes < 1000000 may clash with SM. |
 | 10 Warning in TauDecays::decay: unknown correlated tau production, assuming from unpolarized photon |
 | |
 *------- End PYTHIA Error and Warning Messages Statistics ------------------------------------------------------*

Any idea for fixing this?

Thanks for the help!

Best regards,
Zhao-Huan

Revision history for this message
Olivier Mattelaer (olivier-mattelaer) wrote :

Can you attach the lhe file that PY8 try to shower?
This will allow me to check what is the precision level on the momenta provided to py8.

Thanks,

Olivier

Revision history for this message
Zhao-Huan Yu (yzhxxzxy) wrote :

Hi Olivier,

I have attached the lhe file of my unweighted events.

Thanks,
Zhao-Huan

Revision history for this message
Olivier Mattelaer (olivier-mattelaer) wrote :

Hi,

The madgraph check routines does not spot any issue on the events file. By looking at the first event by eye, the energy-momentum conservation are spot on. The mass of the particles are slightly off but I do not think that pythia complains about that (and this is actually very reasonable discrepancy).

So I would think that the issue is internal to pythia, but I would pass this bug report to someone (chiara) more expert than me on the use of pythia for indirect detection. She might know more.

Cheers,

Olivier

Changed in maddm:
assignee: nobody → Chiara Arina (carina)
Revision history for this message
Chiara Arina (carina) wrote :

Hi,

I will try to have a look at what is going on with pythia but I need to reproduce your error. Could you send me the UFO model file and the param_card.dat for the point that makes pythia crushing?
Also could you send me the script with the exact list of command you use in maddm?

thanks

chiara

Revision history for this message
Zhao-Huan Yu (yzhxxzxy) wrote :

Hi Chiara,

I have attached the UFO model file, the param_card.dat, and the script.

Thanks,
Zhao-Huan

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