PGS 4

PGS stands for Pretty Good Simulator.
This tool was used for the generation of the so called black boxes for the LHC Olympics, and it was used orginally for the "SHW" simulations which provided simulations of the CDF and D0 detector responses (see: arXiv:hep-ph/0010338v2). PGS has become a standard tool to simulate detector responses for theoretical probes of new physics at the LHC. PGS is used with MADGRAPH/MADEVENT (see e-Print: arXiv:0706.2334). Within PGS are complete versions of PYTHIA and TAUOLA (with the modfied D0 Tauola scan).

Installation is thankfully very simple:

INSTALLATION AND RUN

The above is explained on the program website as well.

PGS version 4 contains the ".pyt" files. (top.pyt was just executed.)
These were called ".par" files in the older version of PGS which has
now been relegated to the extensions for the detector cards in PGS 4.

In the directory \PGS\examples\cards
There is a link in the file "zprime.pyt" which is useful.

In general, a card can be run by dropping it into the "cards" folder located under "examples".

Standard Model background cards are available here: Direct Link to Background Data Cards

If you want to specify the luminosity instead of the number of events
change the example command --nev 100 (which generated 100 events)
to an example command --lum 100 (which generates 100 inverse picobarns of data instead). If you plan to change the fortran file "pgs_olympics.f" you must redo the make. That is, put your modified fortran file "pgs_olympics.f" in the "examples" directory and then do:
make clean
make

Two programs have been developed at Northeastern which we dub "SMART" and also a second program recently developed has been dubbed "Parvicursor", both of which processe lhco files with the speed of Chroot (see below) and thus handles large PGS files very efficently.


UPDATED NEW LINK (WIKI) is here: NEW LHCO LINK .
(under analysis tools you will find Harvard's Chameleon)
[One is encouraged to navigate through the LHCO WIKI.
This will allow the user to see the physics content of this WIKI while
at the same teaching the user how the program functions.]

You may want to use PGS 4 with the current version of the Chameleon tutorial (1.01). This avoids any need to worry about backward compatiabilty. (older version of PGS spits out 6 columns of data and does not have the trigger word etc.) To use the older version of Chameleon, say Chameleon .51 execute these commands after you have a lhco file:
cd PGS/examples/CLEAN/
make clean_output

Now, suppose you generated events using the "top.pyt" card, move the output file "top.lhco" to the CLEAN directory and then execute
./clean_output -old top.lhco top.lhco
The output is in the proper form for Chameleon .51 . See the LHCO WIKI for more details.

One may further analyze the produced events from PGS with the package
chROOT available here : chROOT

SLHA, PGS-4, Updated Pythia, and ROOT Analysis Package

There are logical ways to insert your SLHA (SUSY Les Houches Accord) files into Pythia+PGS-4.

One way is to simply insert the SLHA interface in the olympics main
fortran file. You can see an example of this interface in the Pythia tutorial.


An updated version of PGS-4 with a more recent set of Pythia Libraries
beyond what comes with the PGS-4 code has been put together. There is also
a more efficent way to link your SLHA files other than the method just described.

To access both the updated PGS-4 with the more recent Pythia Libraries
and a version of PGS-4 with a very simple add on to get your SLHA into PGS-4,
along with the Parvicursor analysis tool, and some other developments see this
very useful recently developed page by B. Altunkaynak.

After downloading the PGS-4 code with the updates from the above page, one excutes the PGS-4 commands in the same manner as described at the the top of the current page you are reading. However, the change below is to be made (all on the same line of course using for example 1000/pb) :

./olympics --slha cards/suspect2_lha.out --pythia cards/susy.pyt --lum 1000 --L1 --logFile slha_run.log slha_run.lhco

You only need to drop this SLHA file suspect2_lha.out into the cards folder.