The 2025 International Workshop on the High Energy Circular Electron Positron Collider

I present the calculation of complete next-to-leading order electroweak corrections to the Higgs boson production in $gg\to g H$ channel as well as it's rare decay.
We apply the method of differential equations combined with the selection of optimized master integrals to accomplish the calculation of master integrals. We consider three distinct renormalization schemes.
At leading order, the...

Composite asymmetric dark matter (ADM) models provide a well-motivated paradigm that simultaneously explains dark matter (DM) relic density and matter-antimatter asymmetry. In these models, the mass of the DM candidate (the lightest dark baryon) is generated through the dark confinement scale dynamics. Although the leptophilic composite ADM model offers a viable framework, comprehensive...

This presentation details a study of the prospective measurement of the cross-section times branching ratio for Higgs decaying into two photons, $\sigma(e^{+}e^{-} \rightarrow ZH) \times \mathrm{Br}(H \rightarrow \gamma\gamma)$, at the Circular Electron Positron Collider (CEPC). The analysis is performed at a center-of-mass energy of $\sqrt{s} = 240$ GeV, considering the three dominant $Z$...

It is not excluded by the LHC experiments that the SM-like Higgs boson is a mixture of CP eigenstates of opposite parities. In such a scenario, the mixing angle can be measured at CEPC in Higgs to tau-pair decays. We present a preliminary result of the mixing angle measurement obtained with the fast simulation of the CEPC detector.

Embed in Grassmannians, we can obtain the analytical hypergeometric function solutions of multi-loop Feynman integrals with masses. We can make the classification among those hypergeometric solutions by geometric configurations. We can generalize Gauss relations among the hypergeometric functions to complete analytic continuation of the solutions. This method can be applicable to the...

In this talk, I will present a comprehensive study of Higgs boson production associated with a neutrino pair at $e^+ e^−$ colliders ($e^+ e^- \to h \nu \bar{\nu}$) at NLO electroweak (EW) accuracy in both the SM and the two-Higgs-doublet model (2HDM). I will show that new physics effects from the extended Higgs sector can be probed through EW corrections, which lead to deviations from the SM...

The ATLAS and CMS experiments are unique drivers of our fundamental understanding of nature at the energy frontier. In this contribution to the update of the European Strategy for Particle Physics, we update the physics reach of these experiments at the High-Luminosity LHC (HL-LHC) in a few key areas where they will dominate the state-of-the-art for decades to come.

Several excesses around 95 GeV hint at an additional light scalar beyond the Standard Model. We examine the CEPC's capability to test this hypothesis via the Higgsstrahlung channel $e^+e^-\to ZS$ ($Z\to\mu^+\mu^-$, $S\to\tau^+\tau^-/b\bar{b}$). Our results show that a 210 GeV CEPC run with deep neural networks robustly probes the 95 GeV excess, covering large model parameter spaces. We also...

The Future Circular Collider (FCC) is a post-LHC project presenting unparalleled opportunities to thoroughly examine Higgs properties. The electron-positron stage of FCC (FCC-ee), featuring operation modes at 240 and 365 GeV, will produce millions of Higgs bosons through the ZH and VBF processes. Benefiting from the clean experimental environment and the precisely known center-of-mass energy,...

We evaluate the experimental sensitivity to the $CP$-odd admixture in the standard Higgs boson in the process $e^+e^- \to HZ$, which is expected at future lepton collider CEPC with $\sqrt{s}=240~\text{GeV}$ and statistics of $5.6~\text{ab}^{-1}$. Using the Whizard generator with Higgs Characterisation model and DELPHES detector simulation framework we obtain data samples with different...