User Tools

Site Tools


Sidebar

2013:groups:tools:eventformats

This is an old revision of the document!


Event Format : extended LHE

People involved:

Present state

Sample size: example of ttbar dileptonic @ LHC (10,000 events)

File size (Mo)
LHE (gzip compression) 3.8
STDHEP (gzip compression) 153
HEPMC (gzip compression) 346
simplified LHE (gzip compression) 5.1
LHCO (gzip compression) 1.6
Delphes ROOT 161

Motivations

  • defining a format for jet-clustering output (without fast-simulation detector).
  • defining a format which extends the LHCO content (too few information for performing sophisticated analysis).
  • the new format will take into account all Delphes 3 potential.

Some ideas to discuss

  • Using text format. ROOT is rejected ; STDHEP seems to be old.
  • Prefering extending an existing format to defining a totally new one (avoiding developers from coding writer and reader functions from scratch). Our choice is to extend the LHE Format (arXiv:hep-ph/0609017) and its structure based on XML tags. Reminder about the LHE structure:
<LesHouchesEvents version="X">
<header>
...
</header>
<init>
2212     2212  0.40000000000E+04  0.40000000000E+04 0 0 10042 10042 3  1
0.47468358499E+01  0.15068796356E-01  0.47469000000E-03   0
...
</init>
<event>
 12   0  0.4746900E-03  0.2312331E+03  0.7957747E-01  0.1132798E+00
 21   -1    0    0  501  502  0.00000000000E+00  0.00000000000E+00  0.74064204368E+02   0.74064204368E+02  0.00000000000E+00 0.  1.
 21   -1    0    0  502  503  0.00000000000E+00  0.00000000000E+00 -0.74552086368E+03  0.74552086368E+03  0.00000000000E+00 0.  1.
 -6    2    1    2    0  503  0.14952840473E+03 -0.23999735524E+02 -0.41424800778E+03  0.47441561784E+03  0.17473990778E+03 0.  0.
-24    2    3    3    0    0  0.56722398399E+02 -0.36860071438E+02 -0.33540004381E+03  0.35186997544E+03  0.82116958530E+02 0.  0.
  6    2    1    2  501    0 -0.14952840473E+03  0.23999735524E+02 -0.25720865153E+03  0.34516945021E+03  0.17335203433E+03 0.  0.
 24    2    5    5    0    0 -0.16699616992E+03  0.38357854935E+02 -0.25987491067E+03  0.32192128147E+03  0.82093218139E+02 0.  0.
-13    1    6    6    0    0 -0.76026472087E+02  0.53922169130E+02 -0.95737952146E+02  0.13361654188E+03  0.00000000000E+00 0.  1.
 14    1    6    6    0    0 -0.90969697833E+02 -0.15564314195E+02 -0.16413695853E+03  0.18830473960E+03  0.00000000000E+00 0. -1.
  5    1    5    5  501    0  0.17467765185E+02 -0.14358119410E+02  0.26662591415E+01  0.23248168736E+02  0.46999998093E+01 0. -1.
 11    1    4    4    0    0  0.50813684997E+02 -0.61274565657E+02 -0.22556131392E+03  0.23919554619E+03  0.00000000000E+00 0. -1.
-12    1    4    4    0    0  0.59087134026E+01  0.24414494219E+02 -0.10983872989E+03  0.11267442925E+03  0.00000000000E+00 0.  1.
 -5    1    3    3    0  503  0.92806006335E+02  0.12860335914E+02 -0.78847963972E+02  0.12254564240E+03  0.46999998093E+01 0.  1.
</event>
<event>
...
</LesHouchesEvents>
  • Possibility to store hard-process states, hadrons and reco objects in a same file.
  • The generation step (hard-process, shower, reco) will be specified by the status-code.
  • Optional substructure in <event> block: defining a XML tag for each collection of objects. Several collections of a same object kind (jets in the example) can be defined and used.
<hardprocess>
...
</hardprocess>
<jets>
...
</jets>
<jets name="substructure John Hopkins algo">
...
</jets>
<electrons>
...
</electrons>
<muons>
...
</muons>
...
  • List of relevant observables for each object collection must be defined.
  • Name of the format extension: eLHE (e for 'extended') ?
2013/groups/tools/eventformats.1371712230.txt.gz · Last modified: 2013/06/20 09:10 by eric.conte