Exposing the dark sector with future Z factories

• Main Authors: Liu, Jia (Author), Wang, Lian-Tao (Author), Wang, Xiao-Ping (Author), Xue, Wei (Contributor)
• Other Authors: Massachusetts Institute of Technology. Center for Theoretical Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2018-06-04T18:37:03Z.
• Subjects: Article
• Online Access: Get fulltext

 We investigate the prospects of searching dark sector models via exotic Z-boson decay at future e⁺e⁻ colliders with Giga Z and Tera Z options. Four general categories of dark sector models, Higgs portal dark matter, vector-portal dark matter, inelastic dark matter, and axionlike particles, are considered. Focusing on channels motivated by the dark sector models, we carry out a model-independent study of the sensitivities of Z factories in probing exotic decays. The limits on branching ratios of the exotic Z decay are typically O(10⁻⁶-10⁻[superscript 8.5]) for the Giga Z and O(10⁻[superscript 7.5]-10⁻¹¹) for the Tera Z, and they are compared with the projection for the high luminosity LHC. We demonstrate that future Z factories can provide its unique and leading sensitivity and highlight the complementarity with other experiments, including the indirect and direct dark matter search limits and the existing collider limits. Future Z factories will play a leading role in uncovering the hidden sector of the Universe in the future.