Hi, I recently installed Madgraph 2.7.2. I'm using Pythia v8.244 to shower the LHE events however it generated an empty file. I followed the suggestion in this thread: "265962: Pythia8 reading problem LHE file generated by MG5_aMC" and changed the LHE version to 2.0 but still it produces an empty hepmc file. Here is the error log in pythia: *------------------------------------------------------------------------------------* | | | *------------------------------------------------------------------------------* | | | | | | | | | | | PPP Y Y TTTTT H H III A Welcome to the Lund Monte Carlo! | | | | P P Y Y T H H I A A This is PYTHIA version 8.244 | | | | PPP Y T HHHHH I AAAAA Last date of change: 20 Dec 2019 | | | | P Y T H H I A A | | | | P Y T H H III A A Now is 29 Apr 2020 at 22:52:54 | | | | | | | | Christian Bierlich; Department of Astronomy and Theoretical Physics, | | | | Lund University, Solvegatan 14A, SE-223 62 Lund, Sweden; | | | | e-mail: | | | | Nishita Desai; Department of Theoretical Physics, Tata Institute, | | | | Homi Bhabha Road, Mumbai 400005, India; | | | | e-mail: | | | | Ilkka Helenius; Department of Physics, University of Jyvaskyla, | | | | P.O. Box 35, FI-40014 University of Jyvaskyla, Finland; | | | | e-mail: | | | | Philip Ilten; School of Physics and Astronomy, | | | | University of Birmingham, Birmingham, B152 2TT, UK; | | | | e-mail: | | | | Leif Lonnblad; Department of Astronomy and Theoretical Physics, | | | | Lund University, Solvegatan 14A, SE-223 62 Lund, Sweden; | | | | e-mail: | | | | Stephen Mrenna; Computing Division, Simulations Group, | | | | Fermi National Accelerator Laboratory, MS 234, Batavia, IL 60510, USA; | | | | e-mail: | | | | Stefan Prestel; Department of Astronomy and Theoretical Physics, | | | | Lund University, Solvegatan 14A, SE-223 62 Lund, Sweden; | | | | e-mail: | | | | Christine O. Rasmussen; Department of Astronomy and Theoretical Physics, | | | | Lund University, Solvegatan 14A, SE-223 62 Lund, Sweden; | | | | e-mail: | | | | Torbjorn Sjostrand; Department of Astronomy and Theoretical Physics, | | | | Lund University, Solvegatan 14A, SE-223 62 Lund, Sweden; | | | | e-mail: | | | | Peter Skands; School of Physics, | | | | Monash University, PO Box 27, 3800 Melbourne, Australia; | | | | e-mail: | | | | | | | | The main program reference is 'An Introduction to PYTHIA 8.2', | | | | T. Sjostrand et al, Comput. Phys. Commun. 191 (2015) 159 | | | | [arXiv:1410.3012 [hep-ph]] | | | | | | | | The main physics reference is the 'PYTHIA 6.4 Physics and Manual', | | | | T. Sjostrand, S. Mrenna and P. Skands, JHEP05 (2006) 026 [hep-ph/0603175] | | | | | | | | An archive of program versions and documentation is found on the web: | | | | http://www.thep.lu.se/Pythia | | | | | | | | This program is released under the GNU General Public Licence version 2. | | | | Please respect the MCnet Guidelines for Event Generator Authors and Users. | | | | | | | | Disclaimer: this program comes without any guarantees. | | | | Beware of errors and use common sense when interpreting results. | | | | | | | | Copyright (C) 2019 Torbjorn Sjostrand | | | | | | | | | | | *------------------------------------------------------------------------------* | | | *------------------------------------------------------------------------------------* PYTHIA Abort from Pythia::init: Les Houches initialization failed Counting events in input LHEF, please wait. Found 0 events in input LHEF. Start generating events *------- PYTHIA Event and Cross Section Statistics -------------------------------------------------------------* | | | Subprocess Code | Number of events | sigma +- delta | | | Tried Selected Accepted | (estimated) (mb) | | | | | |-----------------------------------------------------------------------------------------------------------------| | | | | | | | | | sum | 0 0 0 | 0.000e+00 0.000e+00 | | | *------- End PYTHIA Event and Cross Section Statistics ----------------------------------------------------------* *------- PYTHIA Error and Warning Messages Statistics ----------------------------------------------------------* | | | times message | | | | 2 Abort from Pythia::init: Les Houches initialization failed | | | *------- End PYTHIA Error and Warning Messages Statistics ------------------------------------------------------* Contribution of sample 0 to the inclusive cross section : 0.00000000e+00 +- 0.00000000e+00 Inclusive cross section: 0.00000000e+00 +- 0.00000000e+00 mb I checked the LHE file and it is not empty. By the way I installed pythia8 separately since i encountered error in installing it within madgraph. The HEPToolInstaller is looking for "pythia82.tgz" but in the Pythia website it has only "pythia83.tgz". Any help is highly appreciated regarding the above error. Sincerely, Dennis

When	Who	Action	New State
2020-04-29	Olivier Mattelaer	Answer	Answered
2020-04-29	Dennis Arogancia	Confirm	Solved
2020-04-30	Dennis Arogancia	Comment	Solved
2021-04-28	klos carolyn	Comment	Solved

MadGraph5_aMC@NLO

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