Name: V. Shtabovenko Date: 07/03/18-03:18:23 PM Z
Hi,
in the vanilla FeynArts this should work out of the box. In the
patched
FeynArts, however,
the masses and couplings are renamed to FCGV[“XYZ”] to avoid
possible
clashes with the
already defined FeynCalc objects:
Options[FAPatch]
So instead of MZ you have FCGV[“MZ”] and so on. Using
SetOptions[InitializeModel,
ModelEdit :> (M$ClassesDescription =
M$ClassesDescription /. {FCGV[“MZ”] -> MZc,
FCGV[“MW”] -> MWc,
FCGV[“MH”] -> MHc})]
InitializeModel[{SM, UnitarySM},
GenericModel -> {Lorentz, UnitaryLorentz}];
gives the desired result.
Cheers,
Vladyslav
Am 03.07.2018 um 18:52 schrieb D. Azevedo:
> Hello Vladyslav,
>
> I imagine this is probably something trivial but I am nonetheless
struggling in adding widths to the internal propagators generated with
FeynArts. In the manual there’s a singular part explaining that
>
> SetOptions[InitializeModel, ModelEdit :>
> (M$ClassesDescription = M$ClassesDescription /. MZ -> MZc)]
>
> should suffice, though in my code
>
> SetOptions[InitializeModel,
> ModelEdit :> (M$ClassesDescription =
> M$ClassesDescription /. {MZ -> MZc, MW -> MWc, MH ->
MHc})]
> InitializeModel[{SM, UnitarySM},
> GenericModel -> {Lorentz, UnitaryLorentz}];
>
> NoElectronHCoupling =
> ExcludeFieldPoints -> {FieldPoint[0][-F[2,
{1}], F[1, {1}], S[3]],
> FieldPoint[0][-F[2, {1}], F[2, {1}],
S[1]],
> FieldPoint[0][-F[2, {1}], F[2, {1}],
S[2]]}
>
> part = InsertFields[
> CreateTopologies[0,
> 2 -> 3], {F[2, {1}], -F[2, {1}]} -> {F[3,
{3}], -F[3, {3}], S[1]},
> Restrictions -> NoElectronHCoupling, InsertionLevel ->
{Classes},
> Model -> {SM, UnitarySM},
> GenericModel -> {Lorentz, UnitaryLorentz}];
> Paint[part, PaintLevel -> {Classes}]
>
> The part pertaining the widths makes no change on the amplitudes
(leading to no widths at the propagators). What am I doing wrong?
>
> Thank you,
> Duarte
>