A warped scalar portal to fermionic dark matter Carmona Bermúdez, Adrián Castellano Ruiz, Javier Neubert, Matthias We would like to thank Miki Chala and Aqeel Ahmed for useful comments on the manuscript, as well as Lukas Mittnacht and Eric Madge for helpful discussions. M.N. thanks Gino Isidori, the particle theory group at Zurich University and the Pauli Center for hospitality during a sabbatical stay. A.C. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 754446 and UGR Research and Knowledge Transfer Found – Athenea3i. The research of J.C. and M.N. is supported by the Cluster of Excellence Precision Physics, Fundamental Interactions and Structure of Matter (PRISMA – EXC 2118/1) within the German Excellence Strategy (project ID 39083149) and under Grant 05H18UMCA1 of the German Federal Ministry for Education and Research (BMBF). We argue that extensions of the SM with a warped extra dimension, together with a new Z2-odd scalar singlet, provide a natural explanation not only for the hierarchy problem but also for the nature of fermion bulk masses and the observed dark matter relic abundance. In particular, the Kaluza-Klein excitations of the new scalar particle, which is required to naturally obtain fermion bulk masses through Yukawa-like interactions, can be the leading portal to any fermion propagating into the bulk of the extra dimension and playing the role of dark matter. Moreover, such scalar excitations will necessarily mix with the Higgs boson, leading to modifications of the Higgs couplings and branching ratios, and allowing the Higgs to mediate the coannihilation of the fermionic dark matter. We study these effects and explore the viability of fermionic dark matter in the presence of these new heavy scalar mediators both in the usual freeze-out scenario and in the case where the freeze-out happens during an early period of matter domination. 2021-02-09T08:00:09Z 2021-02-09T08:00:09Z 2021-01-20 info:eu-repo/semantics/article Carmona, A., Castellano Ruiz, J. & Neubert, M. A warped scalar portal to fermionic dark matter. Eur. Phys. J. C 81, 58 (2021). [https://doi.org/10.1140/epjc/s10052-021-08851-0] http://hdl.handle.net/10481/66395 10.1140/epjc/s10052-021-08851-0 eng info:eu-repo/grantAgreement/EC/H2020/754446 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Springer Nature