# HET-Discovery seminar by Christopher Murphy – University of Copenhagen

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# HET-Discovery seminar by Christopher Murphy

Title: One-Loop Corrections to the Perturbative Unitarity Bound in the $CP$-Conserving Two-Higgs Doublet Model with a Softly Broken $Z_2$ Symmetry

Abstract: We compute all of the one-loop corrections that are enhanced, $O(\lambda_i \lambda_j / 16 \pi^2)$, in the limit $s \gg |\lambda_i | v^2 \gg M_{W}^2$, $s \gg m_{12}^2$ to all the $2 \to 2$ longitudinal vector boson and Higgs boson scattering amplitudes in the $CP$-conserving two-Higgs doublet model with a softly broken $\mathbb{Z}_2$ symmetry. In the two simplified scenarios we study, the typical bound we find from perturbative unitarity is $|\lambda_i(s)| \lessapprox 4$. Preliminary results from a comprehensive numerical fit will also be presented. Based on: 1401.0070, 1512.04567, and work in progress