Revisiting the Higgs-mass calculation in the scale-invariant THDM

TL;DR

This paper recalculates the Higgs-mass spectrum in the scale-invariant Two-Higgs-Doublet Model using direct Feynman diagram methods, revealing significant corrections overlooked in previous effective-potential approaches.

Contribution

It provides a more accurate one-loop Higgs-mass calculation by correcting assumptions in earlier work, showing larger effects on BSM-Higgs masses and mixing.

Findings

One-loop corrections can alter BSM-Higgs mass predictions by about 10%.

Significant mixing between SM-like and BSM states can occur due to these corrections.

Previous effective-potential methods underestimated these effects.

Abstract

We revisit the one-loop calculation of the Higgs-mass spectrum of the scale-invariant THDM, relying on a direct calculation of the relevant Feynman diagrams. We highlight a number of incorrect assumptions in earlier calculations that relied on the effective-potential approach. In contrast with the earlier findings, we show that the one-loop corrections can have an effect of ${\cal O}(10\%)$ on the predictions for the BSM-Higgs masses, and they can also induce non-negligible mixing between the SM-like and BSM states in the neutral-scalar sector.