Showering events from electron photon collision
I'm trying to shower events from electron-photon collisions. The photon beam is generated using a Compton back-scattering PDF and is marked as "from lepton" in MadGraph (lpp2 = 3). After feeding the LHE file into Pythia8, only 22,000 out of 50,000 events are kept. I tried toggling off PartonLevel:ISR and HadronLevel:all, but it didn't help.
Notably, for photon-photon collisions (also with the Compton PDF), there is no such problem. I looked up related issues and found that #621 and #125 may be useful. The only way I have found to keep all events is
turn off the beam remnants
PartonLevel:Remnants = off), but this also requires settingCheck:Event = offandHadronLevel:all = off
as suggested in #621. However, I'm not sure whether this is safe. The statistics table:
*------- PYTHIA Event and Cross Section Statistics -------------------------------------------------------------*
| |
| Subprocess Code | Number of events | sigma +- delta |
| | Tried Selected Accepted | (estimated) (mb) |
| | | |
|-----------------------------------------------------------------------------------------------------------------|
| | | |
| Les Houches User Process(es) 9999 | 50000 50000 21887 | 8.148e-11 3.097e-13 |
| ... whereof user classification code 1 | 50000 50000 21887 | |
| | | |
| sum | 50000 50000 21887 | 8.148e-11 3.097e-13 |
| |
*------- End PYTHIA Event and Cross Section Statistics ----------------------------------------------------------*
*------- PYTHIA Error and Warning Messages Statistics ----------------------------------------------------------*
| |
| times message |
| |
| 28113 Abort from Pythia::next: parton+hadronLevel failed; giving up |
| 2811300 Error in BeamRemnants::setKinematics: no momentum left for lepton beam remnants |
| 281130 Error in Pythia::next: partonLevel failed; try again |
| 1 Warning in Pythia::check: energy-momentum not quite conserved |
| 1 Warning in Pythia::init: be aware that successive calls to init() do not clear previous settings |
| 2 Warning in SLHAinterface::initSLHA: ignoring DECAY tables |
| 2 Warning in SLHAinterface::initSLHA: ignoring MASS entries |
| 5 Warning in SLHAinterface::initSLHA: ignoring QNUMBERS |
| 2 Warning in SLHAinterface::initSLHA: ignoring empty DECAY tables |
| 1 Warning in SLHAinterface::initSLHA: using QNUMBERS for id codes < 1000000 may clash with SM |
| 2 Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off |
| 2 Info from SLHAinterface::initSLHA: importing DECAY tables |
| 2 Info from SLHAinterface::initSLHA: importing MASS entries |
| |
*------- End PYTHIA Error and Warning Messages Statistics ------------------------------------------------------*