The LHC Olympics provides a forum for high-energy champions to go for the gold - discovery of the new particles and phenomena in blinded samples of realistic LHC experiment data. The data are written in a special format in which a list of high-level object four-vectors for the objects in each event appears. The user then runs his or her favorite analysis program on these events, analyzing them for signs of new physics. We will all get together at Santa Barbara in August 2006 to compare our findings.

We provide in the PGS 4 distribution a standard executable called "olympics" in the examples area. Many users could simply unroll the distribution file in some area, put in their favorite PYTHIA card file, and then generate any number of Olympics events by issuing the command "olympics" with certain arguments as specified here:

Usage: olympics <Mode> <Events> [Options] <pgsOutputFile.lhco>

Mode: --pythia <file>
--herwig <processNum> <file>
--stdhep <file>
--lhe <file> --pythia <file>

Events: --nev <num>
--lum <num> (in pb^-1)

Options: [--L2|--L0] [--numToPrint <num>]
[--logFile <file>] [--detector <file>]

Here is an example:

   olympics --pythia cards/top.pyt           \
            --nev 10000 --L2 --numToPrint 5  \
            --logFile top.log top.lhco

Here the user has selected a PYTHIA run (the only kind at present) with 10k events, the L2 (high) trigger thresholds applied, 5 events to be printed out by PYTHIA, written to the LHC Olympics file top.lhco, with a log file sent to top.log.

PGS can process Les Houches Accord Event files using the "--lhe" flag. These partonic level events will be showered by Pythia and simulated by PGS. Note that in addition to the partonic event file, the user must supply a Pythia card file using the "--pythia" flag.

It is a useful exercise, of course, to be able to run one's own Olympics files in order to compare what is in the blinded sample with samples from known signals. In this case, one would like to have access to generator-level information, which is at present not part of the LHC Olympics format so as to avoid tipping off the champions! For guidance on this and other questions, and more detailed documentation, please visit the LHC Olympics Wiki (get the user name and password from Jesse Thaler).

John Conway, Univ. of California, Davis
Problems with this page? Send email. (Last update April 2012.)