Update and unify parameters in default models

[Zachary Marshall]

Hi,

This is admittedly half bug and half feature request. It would be very helpful to update the parameters in the "sm" default model to the newest PDG values. Once that's done, it's a no-brainer to import the changes into other models. But I think this really should be done via imports, rather than by copy-paste as it seems to be now. So for example, in mssm/parameters.py, do something like:

from models.sm.parameters import MW,MZ,WW,WZ # Mass and width of the W and Z

and then not define them in the mssm parameters file. Of course that still allows someone to modify them or overwrite them if they wish!

Thanks,
Zach

[Olivier Mattelaer (olivier-mattelaer)]

Hi Zach,

This is actually a point that should be handle at the FeynRules level (especially the second point).

Cheers,

Olivier

[Zachary Marshall (zach-marshall)]

Hi Olivier,

You can see I just added updated restrict* files for the sm and loop_sm models that should be updated to the new PDG values. We understand that those files are where the values actually come from, and not the parameter.py files - is that right?

You replied that this should be handled at the FeynRules level - does that mean I should send the request to them as well? I'm happy to do - just want to make sure we are on the same page.

Thanks,
Zach

[Olivier Mattelaer (olivier-mattelaer)]

Hi Zachary,

Actually, the restrict file are handle by us and not by FR.
So let me handle this.

Just one question, which value did you use for the width?
The experimental one? The LO one? The NLO one?

Cheers,

Olivier

On Feb 18, 2014, at 2:58 AM, Zachary Marshall <email address hidden> wrote:

> Hi Olivier,
>
> You can see I just added updated restrict* files for the sm and loop_sm
> models that should be updated to the new PDG values. We understand that
> those files are where the values actually come from, and not the
> parameter.py files - is that right?
>
> You replied that this should be handled at the FeynRules level - does
> that mean I should send the request to them as well? I'm happy to do -
> just want to make sure we are on the same page.
>
>
> Thanks,
> Zach
>
> --
> You received this bug notification because you are subscribed to
> MadGraph5_aMC@NLO.
> https://bugs.launchpad.net/bugs/1279095
>
> Title:
> Update and unify parameters in default models
>
> Status in MadGraph5_aMC@NLO Generator:
> New
>
> Bug description:
> Hi,
>
> This is admittedly half bug and half feature request. It would be
> very helpful to update the parameters in the "sm" default model to the
> newest PDG values. Once that's done, it's a no-brainer to import the
> changes into other models. But I think this really should be done via
> imports, rather than by copy-paste as it seems to be now. So for
> example, in mssm/parameters.py, do something like:
>
> from models.sm.parameters import MW,MZ,WW,WZ # Mass and width of the W
> and Z
>
> and then not define them in the mssm parameters file. Of course that
> still allows someone to modify them or overwrite them if they wish!
>
>
> Thanks,
> Zach
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/mg5amcnlo/+bug/1279095/+subscriptions

[Zachary Marshall (zach-marshall)]

Great, thanks Olivier. For the widths we used the experimental ones (PDG2010).

I guess that means that indeed the default parameter cards are generated from these restrict*dat files, and not from the parameters.py files?

Thanks,
Zach

[Zachary Marshall (zach-marshall)]

Hi Olivier,

I just pulled down the new 2.2.3, but I don't see any of this harmonized (different masses in sm and mssm for the W, no imports…). Did I miss something? How did this get fixed?

Thanks,
Zach

[Olivier Mattelaer (olivier-mattelaer)]

Hi,

You right, the correct status is that is going to stay like this then.

I update the status to the correct one.

Cheers,

Olivier

[Zachary Marshall (zach-marshall)]

Hi Olivier,

Ah - I see. Why not? This is a problem for users; is it something fundamental that prohibits the consistency of these parameters across models? It'd be nice to have the same W mass everywhere, for example…

Best,
Zach