Changes between Initial Version and Version 1 of GridDevelopment

05/03/12 17:26:44 (7 years ago)



  • GridDevelopment

    v1 v1  
     3== Technical details for setting up and running the Grid Package ==
     5The full MG/ME package with the grid option is available on our machines.
     7 Using the option
     9   .true.  = gridpack
     11in the {{{
     13}}} will generate a gridpack. At the results page there
     14will be a link to this package.
     16The  gridpackage is what is obtained after a special run of MadEvent
     17and is what is meant  to be sent over to the cluster or grid nodes.
     18It's completely frozen, meaning that you cannot change any parameter
     19anymore, apart from the # of event and the rnd number.
     21When you unpack it you get:
     27The first is a script which accepts two numbers
     28(the number of events and the rnd number).
     31There are two optional packages that can be added to the gridpack:
     32   * DECAY is a optional directory that contains a program that decays final state particles, keeping track of spin correlations at much as possible. It is of particular use for decays of top quarks.
     33   * REPLACE is also an optional directory for lepton replacement. This is usefull for instance in the case where the generation time of the diagrams is critical (like for example in the case of (z/gamma>e, mu, tau)+4 jets including b's).
     34See below for more details
     36==== Basic Use of grid packs ====
     38Before you use locally or over the grid you need to compile
     39the package (compilation does not occur during the run anymore,
     40but beforehand as requested by the grid boys) on a machine
     41compatible with your cluster:
     43cd madevent
     46after that it is ready to go. There is also an option to compile madevent
     47with dynamic libraries. Use
     49./bin/compile dynamic
     51to compile with dynamic libraries for the madgraph source files. This will replace
     52all makefiles with makefile_dynamic and compile using these new makefiles.
     53Using dynamic libraries is greatly encouraged, because it can make the compiled
     54gridpack significantly smaller.
     56After a succesful compilation you can run the
     60script to remove all source files and reduce the size of the package.
     61Now you can just repackage and
     62send it to some cpu in india or run locallly (after chmod +x
     64./ 10000 37
     69==== DECAY ====
     70The DECAY directory contains a program to decay final state particles.
     71It has been designed to keep track of spin correlations as much as possible and
     72is particularly useful for the decay of (anti) top quarks
     73E.g. for the decay of top quarks up to 95% of the correlations are preserved.
     75The DECAY package can be found in the MadGraph v4 developer's kit that can be downloaded from the MadGraph/MadEvent Downloads webpage. Make sure you have a MadGraph/MadEvent version v4.3 or later. To add the package to the gridpack, simply untar the gridpack to get the =./madevent/= directory and the =./ script. Move the DECAY directory from the MG/ME developer's kit to the directory in which you untarred the gridpack, to get here the two directories and the one script file:
     77./madevent/                 ./DECAY/                 ./
     81The DECAY package is compiled automatically when
     85is executed from the ./madevent directory. As input to specify the decays,
     86files with the names
     90should be put in the ./DECAY directory. (Where x is a number between 1 and 20.)
     91These files are read automatically, and one file should be put for each decaying particle. (E.g. for
     92ttbar events 2 files are necessary: one for the decay of the top and one for the anti-top.)
     93The first three lines of these files should be
     99while the fourth line specifies the particle that needs decay, e.g. put
     103for the decay of a top quark. The fifth line is an integer that specifies the decay mode.
     104This depends on the particle that is going to be decayed. For top quarks it is:
     1061 = ' t -> b  w+ '
     1072 = ' t -> b  ve e+'
     1083 = ' t -> b  vm mu+'
     1094 = ' t -> b  vt ta+'
     1105 = ' t -> b  vl l+    (e+mu)'
     1116 = ' t -> b  vl l+    (e+mu+ta)'
     1127 = ' t -> b  j   j    (ud+cs)'
     1138 = ' t -> b  anything (e+mu+ta+ud+cs)'
     115and similar for the anti-top.
     117Hence [ this file] decays all top quarks (ignoring anti-tops!) in the event file leptonically.
     120==== REPLACE ====
     121REPLACE is a package that lets the user replace particles in event files. This is particulary useful to save precious time in the generation of the diagrams. For example, the generation of Z+4jets, in which the Z is decay leptonically, will take (at least) three times longer when the three generations of leptons are specified in the process. Because we know that, if we assume that all of them are massless, the decay of Z bosons is unfavored to any specific lepton flavor, we could as well have generated events with only muons and then randomly replacing the muons in the event file by electrons or tau's with 33% probability for each. This is exactly what the REPLACE script has been designed to do.
     123To add this functionality to the gridpack you'll have to create a directory 'REPLACE" after you have untarred a gridpack to get the following:
     125./madevent/                 ./REPLACE/                 ./
     127The {{{
     129}}} script from the =./madevent/bin/= directory as well as the {{{
     131}}} from the =./madevent/Cards= needs to be copied to the REPLACE directory by typing:
     133cp  ./madevent/bin/  ./madevent/Cards/replace_card1.dat  ./REPLACE/
     135(Note the in the latest version of replace, the '1' add the end of the filename is necessary, and can be any number between 1 and 20, to have the possibility of more than one replace.) In the {{{
     137}}} the particles that needs to be replaced and the particles in which it needs to be replaced have to be specified by their corresponding PDG codes. E.g. adding the lines:
     13911 : 11 13 15
     140-11 : -11 -13 -15
     142will replace all electrons from the event file by electrons (i.e. do nothing), muons or taus with equal probabilities, and simultaneously positrons with positrons, anti-muons and anti-taus. The replace card that can be used in the example above in which only diagrams where the Z decays in muons were generated and need to be replaced by electrons and taus can be found here: [attachment:replace_card1.dat replace_card1.dat]