LHE file structure

Asked by Maksym Ovchynnikov on 2018-09-20

Hi!

I want to extract from unweighted events .lhe file generated by MadGraph the information about the distribution of a given particle. Here is an example of its content:

<event>
 5 1 +1.2391000e+03 8.14124400e+01 7.54677100e-03 1.32509000e-01
       -1 -1 0 0 0 501 -0.0000000000e+00 +0.0000000000e+00 +6.0885452885e+01 6.0885452885e+01 0.0000000000e+00 0.0000e+00 1.0000e+00
        2 -1 0 0 501 0 +0.0000000000e+00 -0.0000000000e+00 -2.7214978938e+01 2.7214978938e+01 0.0000000000e+00 0.0000e+00 -1.0000e+00
       24 2 1 2 0 0 +0.0000000000e+00 +0.0000000000e+00 +3.3670473948e+01 8.8100431823e+01 8.1412439292e+01 0.0000e+00 0.0000e+00
       12 1 3 3 0 0 +1.7212903092e+01 +1.5270134242e-01 -2.3082572549e+01 2.8794313780e+01 0.0000000000e+00 0.0000e+00 -1.0000e+00
      -11 1 3 3 0 0 -1.7212903092e+01 -1.5270134242e-01 +5.6753046497e+01 5.9306118043e+01 0.0000000000e+00 0.0000e+00 1.0000e+00
<mgrwt>
<rscale> 0 0.81412439E+02</rscale>
<asrwt>0</asrwt>
<pdfrwt beam="1"> 1 2 0.41869199E-02 0.81412439E+02</pdfrwt>
<pdfrwt beam="2"> 1 -1 0.93669927E-02 0.81412439E+02</pdfrwt>
<totfact> 0.12563274E+05</totfact>
</mgrwt>
</event>

Could you please tell me what does each string mean? Or where to find the information about it?

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Olivier Mattelaer
Solved:
2018-09-26
Last query:
2018-09-26
Last reply:
2018-09-26
Maksym Ovchynnikov (name-xxx) said : #1

Update: I used the code (http://home.thep.lu.se/~leif/LHEF/LHEFCat_8cc-example.html) to convert the .lhe file to the standard form, and now the output has the form

<event>
    5 1 1239.1 81.4422 0.007546771 0.1325008
       -1 -1 0 0 0 501 -0 0 24.522692 24.522692 0 0 1
        2 -1 0 0 501 0 0 -0 -67.619338 67.619338 0 0 -1
       24 2 1 2 0 0 0 0 -43.096646 92.142029 81.442204 0 0
       12 1 3 3 0 0 -7.3777856 36.846115 -39.298372 54.373063 0 0 -1
      -11 1 3 3 0 0 7.3777856 -36.846115 -3.7982745 37.768967 0 0 1
<weights></weights>
</event>

Could you please tell me what is the meaning of each column? I realize that this is a kind of noob question...

Hi,

That part of the standard is explained in this paper:
https://arxiv.org/abs/hep-ph/0109068

Note that they are two follow-up on the convention:
https://arxiv.org/pdf/hep-ph/0609017.pdf for lhef version2
and
https://arxiv.org/pdf/1405.1067.pdf (for version 3 the one used by MG5aMC)

Cheers,

Olivier

Maksym Ovchynnikov (name-xxx) said : #3

Thanks Olivier Mattelaer, that solved my question.