https://doi.org/10.1140/epjc/s10052-020-7723-2
Regular Article - Theoretical Physics
Leading two-loop corrections to the Higgs boson self-couplings in models with extended scalar sectors
Department of Physics, Osaka University, Toyonaka, Osaka, 560-0043, Japan
* e-mail: braathen@het.phys.sci.osaka-u.ac.jp
Received:
24
December
2019
Accepted:
6
February
2020
Published online:
10
March
2020
We compute the dominant two-loop corrections to the Higgs trilinear coupling 
and to the Higgs quartic coupling 
in models with extended Higgs sectors, using the effective-potential approximation. We provide in this paper all necessary details about our calculations, and present general 
expressions for derivatives of the integrals appearing in the effective potential at two loops. We also consider three particular Beyond-the-Standard-Model (BSM) scenarios – namely a typical scenario of an Inert Doublet Model (IDM), and scenarios of a Two-Higgs-Doublet Model (2HDM) and of a Higgs Singlet Model (HSM) without scalar mixing – and we include all the necessary finite counterterms to obtain (in addition to results) on-shell scheme expressions for the corrections to the Higgs self-couplings. With these analytic results, we investigate the possible magnitude of two-loop BSM contributions to the Higgs self-couplings and the fate of the non-decoupling effects that are known to appear at one loop. We find that, at least as long as pertubative unitarity conditions are fulfilled, the size of two-loop corrections remains well below that of one-loop corrections. Typically, two-loop contributions to amount to approximately 20% of those at one loop, implying that the non-decoupling effects observed at one loop are not significantly modified, but also meaning that higher-order corrections need to be taken into account for the future perspective of precise measurements of the Higgs trilinear coupling.
© The Author(s), 2020
