Downloads

• Dowload the latest version of the source code for CHARYBDIS2 into the directory where you plan on using it. There is also an alternative implementation with an extra model for graviton emission and a model for a string ball due to D. Gingrich which can be used by setting the flag EXTRA = GINGRICH in the corresponding Makefile.
• Extract the contents of the zipped file on that directory.
• Download the data_files and extract them into a directory called data_files. If this step has been done in your CHARYBDIS2 execution directory then you don't have to do anything else, otherwise create a symbolic link in there named data_files, pointing to the actual data_files directory.

HERWIG users

1. Get the latest version of the HERWIG source code. This must include herwig*.f herwig*.inc and HERWIG*.INC where * is the version number. Download these files into the CHARYBDIS2 directory.
   
2. Open herwig*.f with a text editor and delete the dummy Les Houches subroutines UPINIT and UPEVNT and the dummy PDFLIB subroutines PDFSET abd STRUCTM.
   
3. Open the Makefile. Here you only have to make sure that the flags are set correctly.
   
   • Set the generator flag to GENERATOR = HERWIG.
   • Set the name of the herwig source code file to the correct value, i.e. HERWIGSRC = herwig*.f
   • If you just want to use HERWIG's internal pdfs leave PDFCHOICE =            (i.e. blank). Alternatively you can use PDFLIB by setting PDFCHOICE = PDFLIB, but you will have to install it separately and set the path to the instalation directoty of the library by defining LPDF = path_spelled_out.
     
4.  Now everything is set to run. There is a main program called mainherwig.f  which you can edit to set the parameters for the run. If you want to run different samples there are two things to be done:
• Set the beam parameters in the begining of the INITIALISATION section. That will be IDBMUP and EBMUP. You can also choose the number of events to run here by setting MAXEV. A couple of lines down you can also change the seeds for the random number generator and control how many events are printed on screen.
• The physical parameters of the model for the hard process, as well as any other switches in the program (see manual and/or "readme" file for a detailed list) can be changed from the default values (which are initialised internally in the source charybdis2-*.*.*.F) by editing CHDEFAULTS.
• NEW!!! (18 Sep 2009): Any parameter for the run that you have initialised is overrun by a charybdis2.init file. If you do not wish to use the charybdis2.init file you need to comment the CHREADINITFILE call in the main program. For more information see the charybdis2.init file provided in the tar ball.
5. Finally, if you wish to create your own analysis, you may use the subroutines HWABEG, HWANAL and HWAEND which are initialisation, event by event calculations, and final analysis subroutines respectively.
6. Now you only need to compile (type make) and run (type ./charybdis2-*.*.*.exe). If you wish to clean the compiled files to recompile from scratch you can do "make clean".

PYTHIA users

1. Get the latest version of the PYTHIA source code . This file should be of the form pythia*.f where * is the version number. Download it into the CHARYBDIS2 directory.
   
2. Open pythia*.f with a text editor and delete the dummy Les Houches subroutines UPINIT and UPEVNT and the dummy PDFLIB subroutines PDFSET abd STRUCTM.
   
3. Open the Makefile. Here you only have to make sure that the flags are set correctly.
   
   • Set the generator flag to GENERATOR = PYTHIA.
   • Set the name of the pythia source code file to the correct value, i.e. PYTHIASRC = pythia*.f 
   • If you just want to use PYHTHIA's internal pdfs leave PDFCHOICE =            (i.e. blank). Otherwise you can also use PDFLIB by setting PDFCHOICE = PDFLIB, but you will have to install it separately and set the path to the instalation directory of the library by defining LPDF = path_spelled_out.
     
4.  Now everything is set to run. There is a main program called mainpythia.f  which you can edit to set the parameters for the run. If you want to run different samples there are two things to be done:
• Set the beam parameters in the begining of the INITIALISATION section, by changing the arguments of PYINIT. 
• The physical parameters of the model for the hard process, as well as any other switches in the program (see manual and/or "readme" file for a detailed list) can be changed from the default values (which are initialised internally in the source charybdis2-*.*.*.F) by editing CHDEFAULTS.
• NEW!!! (18 Sep 2009): Any parameter for the run that you have initialised is overrun by a charybdis2.init file. If you do not wish to use the charybdis2.init file you need to comment the CHREADINITFILE call in the main program. For more information see the charybdis2.init file provided in the tar ball.
5. Finally, if you wish to create your own analysis, you may use the subroutines CHARYBEG, CHANAL  and CHAEND which are initialisation, event by event calculations and final analysis subroutines respectively.
6. Now you only need to compile (type make) and run (type ./charybdis*.exe). If you wish to clean the compiled files to recompile from scratch you can do "make clean".

CHARYBDIS parton level only

1. For this implementation you must have either LHAPDF or PDFLIB (part of CERNLIB) installed.
2. Open the CHARYBDIS2 Makefile. Here you only have to make sure that the flags are set correctly.
   
   • Set the generator flag to GENERATOR = CHARYBDIS
   • Set PDFCHOICE = PDFLIB or LHAPDF, according to which one you have installed.
   • Set the flag which defines the path to your pdf library LPDF = pdf_path (see examples in the Makefile).
3.  Now everything is set to run. There is a main program called maincharybdis.f  which you can edit to set the parameters for the run. If you want to run different samples you can change the physical parameters of the model for the hard process, as well as any other switches in the program (see manual and/or "readme" file for a detailed list) from the default values (which are initialised internally in the source charybdis2-*.*.*.F) by editing CHDEFAULTS.
4. NEW!!! (18 Sep 2009): Any parameter for the run that you have initialised is overrun by a charybdis2.init file. If you do not wish to use the charybdis2.init file you need to comment the CHREADINITFILE call in the main program. For more information see the charybdis2.init file provided in the tar ball.
5. Finally, if you wish to create your own analysis, you may use the subroutines CHARYBEG, CHANAL  and CHAEND which are initialisation, event by event calculations and final analysis subroutines respectively.
6. Now you only need to compile (type make) and run (type ./charybdis2-*.*.*.exe). If you wish to clean the compiled files to recompile from scratch you can do make clean.