Warning in NMSSM

[MailQuestion]

Hello Florian Staub,

Sorry to bother you, I am currently working in an implementation of a new model in SARAH (excelent tool by the way) but i was facing an issue that i was not able to work out.
In fact i find the same Warning when i run the NMSSM model, the one that comes with the program.

If i run:

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Start["NMSSM"]

and then

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CheckModel[]

I get the following warning about a possible mixing between hh and Ah:

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Lagrangian::PossibleMixing: "Possible mixing between hh and Ah induced by the term: 1/4 I (Sqrt[2]\ (-(conj[T[\[Lambda]]]-T[\[Lambda]])\ ((Times[<<2>>]+Times[<<2>>])\ ZH[gt1,1]+(Times[<<2>>]+Times[<<2>>])\ ZH[gt1,2])+(-(conj[<<1>>]+Times[<<2>>])\ (Times[<<2>>]+Times[<<2>>])+2\ vS\ (conj[<<1>>]+Times[<<2>>])\ ZA[gt2,3])\ ZH[gt1,3])+\[Lambda]\ conj[\[Kappa]]\ (<<1>>)+\[Kappa] conj[\[Lambda]] (<<1>>))"

Is this correct or i am doing something in a wrong way? I was wondering if this could bring some problems in the following calculations or if there is a way to define or extend the definition of some variables to solve this warning.

[FStaub]

Hi,

this is the expected behaviour. The reason is that only for specific choices for the imaginary parts of the parameters, no mixing between CP even and odd states appears. See for instance the discussion in 0906.0777, sec. 3.3. Thus, in the general case (this is what SARAH checks), there is a mixing between hh and Ah which you should take into account if you want to study CP violation. This is done in the model file NMSSM-CPV.

Cheers,
Florian