Name: V. Shtabovenko Date: 12/03/19-11:07:20 AM Z


Short answer: Whenever your g^5 prescription violates Ward-Takahashi and
Slavnov-Taylor identities, finite counterterms are required to fix
those. But there is no
cookbook recipe to calculate the counterterms for arbitrary processes at
arbitrary order
in perturbation theory. Moreover, explicitly checking that all relevant
identities are
satisfied can be also quite cumbersome.

I’m not an expert on 2HDM so I can’t help you here. It usually takes
some thinking and
tinkering to check what parts of the calculation are influenced by the
choice of g^5 scheme, cf. e.g. arXiv:1907.00997

Am 03.12.19 um 04:55 schrieb David Wang:
> In FeynCalc-9.3, I read “BMHV is algebraically consistent but often suffers from nonconservation of currents in the final results. The conservation must be then enfornced by introducing finite counter-terms. The counter-terms are to be supplied by the user, since FeynCalc does not do this automatically”.
> I want to know under what circumstances we need to introduce finite counter-terms.
> And when I calculate Charged Higgs decay into W boson and Z boson in the 2HDM model at two loop level, Do I need to add some finite counter-terms by hand?
>