Recola FAQ

This is a list of Frequently Asked Questions about Recola

Why …

… do I get different numbers with other tools?

There are many reasons for finding disagreement with other tools. The most common mistake is a different set of input parameters. With Recola2 you can print all internal and derived parameters by setting

from pyrecola import *
set_print_level_parameters_rcl(2)

which allows for a direct comparison of all used parameters.

For a technical/precision comparison we recommend switching off the Complex-Mass scheme (CMS) and setting all widths to zero. Furthermore, Recola has a different convention for finite parts of loop-amplitudes. Comparing to OpenLoops or Madgraph requires to set

from pyrecola import *
from math import pi
set_delta_ir_rcl(0,pi**2/6)

How do I…

… visualize contributions to processes?
Recola supports for drawing branches with set_draw_level_branches_rcl(), which, after invoking generate_processes_rcl(), will generate TeX files in the current working directory. The TeX files can be compiled and transformed to postscript with the programs latex and dvips and require the Axodraw package.