ILC Workshop on Potential Experiments (ILCX2021)

CP Violation in Higgs-τ−τ Coupling

28 Oct 2021, 11:00

20m

Room #2 (Zoom Meeting ID: 823 6921 2312)

Oral presentation using Zoom Session F: Higgs properties F-1: Higgs properties

Speaker

Pedro PASQUINI (Shanghai Jiao Tong University)

Description

We demonstrate how probes of CP-violating observables in Higgs di-tau decays at prospective future lepton colliders could provide a test of weak scale baryogenesis with significant discovery potential. Measurements at the Circular Electron Positron Collider, for example, could exclude a CP phase larger than ${2.9}^{\circ }$ (${5.6}^{\circ }$) at 68\% (95\%) C.L. assuming the Standard Model value for the magnitude of the tau lepton Yukawa coupling. Conversely, this sensitivity would allow for a 5$\sigma$ discovery for 82\% of the CP phase range [0,2$\pi$). The reaches of the Future Circular Collider-ee and International Linear Collider are comparable. As a consequence, future lepton colliders could establish the presence of CP violation required by lepton flavored electroweak baryogenesis with at least 3$\sigma$ sensitivity. Our results illustrate that Higgs factories are not just precision machines but can also make $\mathcal{O}$(1) measurement of the new physics beyond the Standard Model.

Presentation materials

Higgs_tau_tau_ILCX2021_PedroPasquini.pdf