propagators.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
# This file was automatically created by FeynRules 2.0 (static file)
# Mathematica version: 8.0 for Mac OS X x86 (64-bit) (November 6, 2010)
# Date: Mon 1 Oct 2012 14:58:26
 
from object_library import all_propagators, Propagator
 
# define only once the denominator since this is always the same
denominator = \
    "P('mu', id) * P('mu', id) - Mass(id) * Mass(id) + complex(0,1) * Mass(id) * Width(id)"
 
# propagator for the scalar
S = Propagator(name='S', numerator='complex(0,1)', denominator=denominator)
 
# propagator for the incoming fermion # the one for the outcomming is computed on the flight
F = Propagator(
    name='F',
    numerator="complex(0,1) * (Gamma('mu', s1, s2) * P('mu', id) + Mass(id) * Identity(s1, s2))",
    denominator=denominator)
 
# massive vector in the unitary gauge, can't be use for massless particles
V1 = Propagator(
    name='V1',
    numerator="complex(0,1) * (-1 * Metric(l1, l2) + Metric(l1,'mu')* P('mu', id) * P(l2, id) / Mass(id)**2 ",
    denominator=denominator)
 
# massless vector and massive vector in unitary gauge
V2 = Propagator(name='V2', numerator='complex(0,-1) * Metric(l1, l2)',
                denominator="P('mu', id) * P('mu', id)")