Changes between Version 9 and Version 10 of FormFactors

Timestamp:

Dec 12, 2013, 11:45:04 AM (11 years ago)

Author:

Olivier Mattelaer

Comment:

--

FormFactors

@@ -1 @@
-=== How to add momentum dependent form factors? in UFO model===
-
-=== Compatible model.
+[[PageOutline(1,Page Contents,inline)]]
+
+= Method 1: Pure Python (UFO/ALOHA) =
+
+== Compatible model. ==
 
 All UFO model are not ready to use form-factor (all recent one should be).
@@ -15 +17 @@
 }}}
 
-=== Defining your form factor:
+== Defining your form factor: ==
 
 create/edit the file form_factors.py
@@ -37 +39 @@
 
 
-=== Add the vertex dependencies in your form factor:
+== Add the vertex dependencies in your form factor: ==
 
 Go in the file vertices.py and identify the interactions that you want to modify:
@@ -84 +86 @@
 
 
-=== For More complex formfactor (Those who cann't be written in one line).
+= Method 2: Fortran Way =
+This method is intended for More complex formfactor (Those who cann't be written in one line).
 
 If the formfactor is a very complex function with a lot of "if" statement (like those obtained if when you add a form-factor to have the vertex associated to a full loop).
@@ -115 +118 @@
 }}}
 
-=== How to add momentum dependent form factors? in v4 model===
+= Method 3: Expert Mode =
+
+You can fully bypass ALOHA by setting the lorentz structure to external
+{{{
+VVS2 = Lorentz(name = 'VVS2',
+               spins = [ 3, 3, 1 ],
+               structure = 'external')  
+}}}
+You are then '''responsible''' to provide the functions yourself. 
+Each routines (VVS2_0.f, VVS2_1.f, ..., VVS2_0.py, ...) need to be set in the directory UFO_DIR/Fortran, UFO_DIR/Python, UFO_DIR/CPP
+
+A typical way to use this mode is first to ask MG5 to create those files (via the mg5 command output aloha VVS2_0 --format=Fortran).
+Then set the structure on external and modify manually the file created by ALOHA.
+
+
+
+= V4 MODEL (OLD model format)=
+
 The easiest way to implement momentum dependent form factors, without changing all the details in the 
 {{{
@@ -214 +234 @@
 in the model directory so that you won't forget for which process you created this model.)
 
--- Main.RikkertFrederix - 20 Jul 2008
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