delta rho calculation

[valevale]

Dear Florian,

we are studying a SM model extension (no SUSY) with extra triplet and doublet scalars.
We have noticed that the calculation of the delta(rho) low-energy parameter is very different using different versions. Notably:

-delta(rho) = 3.38626505E-04 using SARAH 4.6.0 and SPheno 3.3.8
-delta(rho) = 1.01887168E-02 using SARAH 4.9.1 and SPheno 4.0.3

We are using the same model file and same input parameters… The big difference is introduced in the loop corrections (especially that of M_W).
In the latter case, for other combinations of input parameters we are getting values of delta(rho) as large as ~O(1-10), which definitely look wrong.
We tried to switch off the loop calculation for the masses (flag 55 of SPheno) but the low-energy observables seem to ignore that flag..

Could you perhaps help us understanding what is going on?
Thanks so much in advance.
Best,
Valentina

[FStaub]

Version 4.9.X is already three years old. Did you check the most recent version?