Programme

O.6 -- Oral, VCTP-50

Date: Tuesday, 5 August 2025

Time: 11:10 - 11:35

Exploring CP Violation and EDM Cancellation in a Scale-Invariant g2HDM

Nguyen Dang Bao Nhi (1), Eibun Senaha (2,3)

(1) Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University; (2) Subatomic Physics Research Group, Science and Technology Advanced Institute, Van Lang University; (3) Faculty of Applied Technology, School of Technology, Van Lang University

Recent LHC data indicate that the discovered scalar particle with a mass of 125 GeV closely resembles the predictions of the Standard Model (SM). While the scale of new physics could lie well above the TeV range, current observations do not rule out scenarios in which new particle masses are below the TeV scale, provided their couplings to SM particles are "aligned" to mimic SM-like behavior. Another significant experimental development is the stringent limit on the electron electric dipole moment (EDM), which strongly constrains CP-violating effects in the Higgs sector. In this talk, we explore a scale-invariant general two-Higgs-doublet model (SI-g2HDM) with explicit CP violation. Using the method of Gildener and Weinberg, we analyze the Higgs mass spectrum and couplings at the one-loop level, focusing on CP violation originating from both the scalar and Yukawa sectors. We demonstrate that tree-level CP mixing vanishes along a flat direction, resulting in SM-like Higgs couplings to gauge bosons and fermions that satisfy current LHC constraints. At the one-loop level, CP violation in the Higgs sector is entirely determined by the additional Yukawa couplings. Furthermore, in the presence of a complex top Yukawa coupling ($\rho_{tt}$), we find that the electron EDM vanishes when $\mathrm{arg} = n \pi/2$, where $n$ is an integer. This behavior is in sharp contrast to that in the conventional general 2HDM. Time permitting, we will also discuss cases involving a nonzero additional electron Yukawa coupling.

Presenter: Senaha Eibun