Changes between Initial Version and Version 1 of MadDipole

03/20/12 16:17:11 (8 years ago)



  • MadDipole

    v1 v1  
     3=== MadDipole: Automated Dipole Subtraction for NLO Calculations. ===
     5MadDipole is a MadGraph package that has been developed to automate the calculation of the subtraction terms for any NLO (in QCD) calculation. It can generate the subtraction terms for the reals as well as for the virtuals in both the massless and massive cases. More information can be found here [ arXiv:0808.2128] and here [ arXiv:1004.2905]
     7==== Running the code ====
     9To run the code, download the package {{{MG_ME_DIP_V?.?.?.tar.gz}}} (!MadDipole) or the {{{MG_ME_V?.?.?.tar.gz}}} (Developer's kit), where V?.?.? is version V4.4.35 or later from the [ MadGraph download page] ([ mirror]). (Registration is needed and can be done via a link from the MadGraph/MadEvent main site).
     10   1. Go to the {{{MadGraphII}}} directory and type {{{ make }}}
     11   1. Copy the {{{Template}}} directory to a new process directory of your choice, e.g. {{{MyProcDir}}}, to keep a clean copy of the Template directory as usual.
     12   1. If you have downloaded the Developer's kit: go to this new directory and activate the 'dipole mode' by typing: {{{ ./bin/standalone_dipole }}} This should activate the dipole terms and remove all files that are not needed. This step can be skipped if !MadDipole ( {{{MG_ME_DIP_V4.4.??.tar.gz}}}) was downloaded.
     13   1. The next step is to specify the process in the =./Cards/proc_card.dat=. This should be the m+1 particle process, i.e. the process including the emission of the extra particle.
     14   1. Then generate the diagrams including subtraction terms by typing {{{ ./bin/newprocess }}} This will also compile the HELAS and MODEL libraries.
     16Like for a normal MadGraph run, this will generate one (or more) directory(ies) inside the =./SubProcesses= directory in which the a code specific for the particular process is generated. A simple program to check the results, {{{check_dip.f}}}, has been provided to calculate the m+1 matrix element and the subtraction terms for any point in phase space. By default the program {{{check}}} prints a table with the matrix element squared and the subtraction terms on the screen for which each point is closer to a collinear of soft limit. Another check program, {{{check_intdip.f}}}, checks the sum of the integrated dipoles for a random (or given) phase-space point. It can be compiled by typing {{{make checkint}}} in the processes directories.
     18=== MadDipole for QED ===
     20MadDipole can also generate subtraction terms necessary for QED corrections for both massless and massive cases. More information can be found here
     22Running the code is very similar to the QCD case described above. If you have downloaded the developer's kit (MG_ME_V?.?.?.tar.gz) the dipole mode for QED will be activated by running
     23{{{ ./bin/standalone_dipole_qed .
     26The matrix element and the subtraction terms are then generated by running
     27{{{ ./bin/newprocess_qed .
     30In the case you have downloaded only MadDipole (MG_ME_DIP_V4.4.??.tar.gz) the script newprocess_qed is already present.
     32For the QED case the following lines should be present in your /Cards/proc_card.dat:
     38The logical variable DipolePhotonPDF determines whether an initial state photon comes out of a hadron or is a free particle. In the first case it is assumed that a pdf is present. If these lines are missing this variable is set to false.
     40The QED version contains a check program identical to the QCD one for checking the limits of the unintegrated subtraction terms. A check program for the integrated subtraction terms is not present, as depending on the actual process one or several phase space points are required as input.
     42The check program is compiled by typing {{{make}}} which produces an executable {{{check_qed}}}.
     43=== <br /> Note: ===
     45When using MadDipole a minimum of 1GB RAM is required otherwise the process may be killed by the operating system.