New Model Beynod the Standard Model Formulation

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Discussion Overview

The discussion revolves around the installation of CompHep, an event generator, on a Linux OS (Fedora 17) while exploring a new model beyond the Standard Model that incorporates B-L symmetry. Participants share technical challenges related to software dependencies and suggest alternative approaches for model implementation.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant reports an error related to the absence of the library 'lg2c' during the installation of CompHep, despite having installed GCC, libX11, and g77.
  • Another participant suggests that packaging issues between gfortran and gcc during the transition from gcc3.x to gcc4 may be contributing to the problem and recommends adjusting installed packages.
  • There is a suggestion to use a combination of MadGraph 5 and the Feynrules Mathematica package as an alternative to CompHep, highlighting its ease of use and existing MSSM implementation.
  • Participants discuss the need for either g77 or gfortran depending on the version of gcc, indicating uncertainty about which is necessary for the user's setup.
  • One participant notes that issues with MadGraph and MadEvent arise from the interchangeable use of g77, f77, and gfortran, which can vary across different gcc releases and architectures, particularly affecting 64-bit systems.

Areas of Agreement / Disagreement

Participants express differing views on the best approach to resolve the installation issue, with some advocating for the use of alternative software while others focus on troubleshooting the existing setup. No consensus is reached regarding the optimal solution.

Contextual Notes

Participants mention potential complications arising from the transition between different versions of gcc and the associated Fortran compilers, as well as the varying behavior of these compilers on different architectures.

Who May Find This Useful

Individuals interested in particle physics modeling, software installation on Linux, and those exploring alternative computational tools for theoretical physics may find this discussion relevant.

welatiger
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Hi;


I'm working on a new model beynod the standard model one of MSSM with B-L symmetry
I'm trying to install CompHep (Event Generator) on Linux OS (Fedora 17)
but always i get the same error

gcc -o bin/tab_view.exe src/plot/view_tab.o -lnum -lserv -Llib -lX11 -lm -lg2c
/usr/bin/ld: cannot find -lg2c
collect2: ld returned 1 exit status
make: *** [link] Error 1


i have already installed
1)GCC.
2)libX11 package.
3)g77 Compiler.

I don't Know what is the Problem

many thanks
 
Physics news on Phys.org
+1 to the B-L

gfortran and gcc have packaging problems during the transition from gcc3.x to gcc4. Note I say "gfortran"; one of the problems was the change of flavour of the fortran compiler. It could help if you install or uninstall some packages in Fedora.
 
i'm sorry i don't understand
do you mean i must install gfortran
can i talk you from E-mails
 
Use a combination of madgraph 5 and the Feynrules mathematica package instead of CompHEP. You can just drop your lagrangian into Mathematica, and everything else is taken care of for you. Its much easier to use, especially if you aren't familiar with all the headaches that can arise because of the switch from g77 to gfortran. I think the Feynrules page even has an MSSM implementation that should be easy to modify for your purposes.
 
Ok How can i implement such a model in mathematica
 
welatiger said:
i'm sorry i don't understand
do you mean i must install gfortran
can i talk you from E-mails

Yes I mean that depending of your version of gcc you can need either g77 or gfortran. I am sorry I do not remember the details.
 
Ok thank you for your concern
 
Ok How can i implement such a model in mathematica

Download the feyrules package (google it). Download the MSSM implementation. Modify the lagrangian as necessary. Use the madgraph output format.

To generate events, download madgraph 5, follow the instructions to point it to the output files from feynrules.
 
One issue with MG/ME is that they use g77, f77 and gfortran, sometimes interchangably, sometimes not, and different gcc releases and different architectures treat those three aliases differently. In particular, 64-bit is usually a lot fussier than 32-bit. I don't think there is a simple solution, although running on a 32-bit machine usually helps.
 

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