Light lepton portal dark matter meets the LHC

• Published in: The journal of high energy physics Vol. 2023; no. 3; pp. 10 - 30
• Main Authors: Iguro, Syuhei, Okawa, Shohei, Omura, Yuji
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2023; Springer Nature B.V; SpringerOpen
• Subjects: Classical and Quantum Gravitation; Dark matter; Dark Matter at Colliders; Electroweak model; Elementary Particles; High energy physics; Large Hadron Collider; Leptons; Luminosity; Models for Dark Matter; Multi-Higgs Models; New Light Particles; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Scalars; Searching; String Theory; New Light Particles; Dark Matter at Colliders; Models for Dark Matter; Multi-Higgs Models
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2023)010

A bstract We examine the sensitivity of the Large Hadron Collider (LHC) to light lepton portal dark matter with its mass below 10 GeV. The model features an extra doublet scalar field and singlet Dirac dark matter, which have Yukawa interactions with left-handed leptons. To correctly produce the dark matter abundance via the thermal freeze-out, a large mass splitting among the extra scalars is required, thus providing a light neutral scalar below O 10 GeV and heavy neutral and charged scalars at the electroweak scale. In this paper, we focus on the electroweak pair-production of the extra scalars with subsequent model-specific scalar decays and evaluate the current constraints with the LHC Run 2 data and the discovery potential at the High Luminosity LHC (HL-LHC). It turns out that a large part of the theoretically allowed parameter space can be tested at the HL-LHC by taking into account complementarity between slepton searches and mono- Z plus missing transverse energy search. We also discuss same-sign charged scalar production as a unique prediction of the model, and the implication of the collider searches in the thermal dark matter scenario.