8 from object_library
import all_propagators, Propagator
12 "P('mu', id) * P('mu', id) - Mass(id) * Mass(id) + complex(0,1) * Mass(id) * Width(id)"
15 S = Propagator(name=
'S', numerator=
'complex(0,1)', denominator=denominator)
18 F = Propagator(name=
'F',
19 numerator=
"complex(0,1) * (Gamma('mu', s1, s2) * P('mu', id) + Mass(id) * Identity(s1, s2))"
20 , denominator=denominator)
23 V1 = Propagator(name=
'V1',
24 numerator=
"complex(0,1) * (-1 * Metric(l1, l2) + Metric(l1,'mu')* P('mu', id) * P(l2, id) / Mass(id)**2 "
25 , denominator=denominator)
28 V2 = Propagator(name=
'V2', numerator=
'complex(0,-1) * Metric(l1, l2)',
29 denominator=
"P('mu', id) * P('mu', id)")