- #1

- 219

- 2

## Main Question or Discussion Point

Hi all,

I'm little confused about the unitarity and perturbativity constrains which imposed on a potential's parameters, like 2HD potential. Look for example: [arXiv:1507.03618v3 [hep-ph]]

First, I'd like to know what is most essential ? I mean if unitarity constraind ## \lambda##

to say less than 20 and as it's well known perturbativity constraind ## \lambda## to < 4 pi, so what's the most restricted value for ## \lambda## ?

I think being the coupling perturbative is essential so that the theory be finite at higher order correction , so the coupling value in general can't exceed 4 pi .. is it right ?

But for instance in [arXiv:1303.2426v2 [hep-ph]], subsection (III, A), they consider only the unitarity constrain, reaching for ## \lambda## values to ~ 35 ! and say the unitarity constrain is more important than perturbation .. this looks little bit strange for me ..

Does any one has an idea ..

I'm little confused about the unitarity and perturbativity constrains which imposed on a potential's parameters, like 2HD potential. Look for example: [arXiv:1507.03618v3 [hep-ph]]

First, I'd like to know what is most essential ? I mean if unitarity constraind ## \lambda##

to say less than 20 and as it's well known perturbativity constraind ## \lambda## to < 4 pi, so what's the most restricted value for ## \lambda## ?

I think being the coupling perturbative is essential so that the theory be finite at higher order correction , so the coupling value in general can't exceed 4 pi .. is it right ?

But for instance in [arXiv:1303.2426v2 [hep-ph]], subsection (III, A), they consider only the unitarity constrain, reaching for ## \lambda## values to ~ 35 ! and say the unitarity constrain is more important than perturbation .. this looks little bit strange for me ..

Does any one has an idea ..