[tw-hepnet] NCTS Seminar - Particle Physics Journal Club 2026/04/10 (Fri.) 12:00

[Yu-Rou Tsang]

***NCTS Seminar***

Particle Physics Journal Club

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Speaker: Prof. Hsin-Chia Cheng (UC Davis)

Talk title: Dark Matter on a Slide

Time: 2026/04/10 (Fri.) 12:00

Place: NCTS Physics 3F R307, Cosmology Hall, NTU

 

Abstract:
We study GeV-scale dark matter composed of dark pions from a confining non-Abelian gauge group of the dark sector. The thermal relic density is determined by the interplay of the up-scatterings of dark pions to heavier dark kaon and eta states, and the decay of the unstable dark eta to the Standard Model. The mechanism is analogous to a playground slide, where one climbs up first and then slides down with a release of energy. A discrete symmetry renders both direct and indirect dark matter detections mostly ineffective. The most prominent signatures are dark eta decays in accelerator experiments. Their productions crucially depend on the portal interactions between the Standard Model and the dark sector. We illustrate this scenario with a minimal model based on the SU(3)/SO(3) coset in the dark sector.  A correct dark matter relic density can be obtained with mass splittings of 10% -- 50% among dark mesons, and the lifetime of the dark eta less than ~10^3 m/c. Displaced decay vertices and long-lived particle searches from dark showers will have good sensitivities to this model.