The continuum linear dilaton Megías Fernández, Eugenio Quirós, Mariano We would like to thank O.J.P. Eboli, M. Perez-Victoria and L.L. Salcedo for fruitful discussions. The work of E.M. is supported by the Spanish MINEICO under grant FIS2017-85053-C2-1-P, by the FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento 2014-2020 Operational Programme under grant A-FQM-178-UGR18, by Junta de Andalucia under grant FQM-225, and by the Consejeria de Conocimiento, Investigacion y Universidad of the Junta de Andalucia and European Regional Development Fund (ERDF) under grant SOMM17/6105/UGR. The research of E.M. is also supported by the Ramon y Cajal Program of the Spanish MINEICO under grant RYC-2016-20678. The work of M.Q. is partly supported by the Spanish MINEICO under grant FPA2017-88915-P, by the Catalan Government under grant 2017SGR1069, and by the Severo Ochoa Excellence Program of MINEICO under grant SEV-2016-0588. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Continuum spectra can be a way out to alleviate the tension generated by the elusiveness of narrow resonances of new physics in direct experimental searches. Motivated by the latter, we consider the linear dilaton model with a continuum spectrum of KK modes. It is provided by a critical exponential bulk potential for the scalar field stabilizing the distance, between the UV boundary at y = 0 and a naked (good) singularity at y = y(s), in proper coordinates, which corresponds in conformal coordinates to z(s) -> infinity. The cutoff M s in this theory is an intermediate scale M-s similar or equal to 10(-5) M-P(1) and the warped factor solves the hierarchy between M-s and the TeV, while the hierarchy between M-P1 and M-s has to be solved by a (Little) String The- ory with coupling g(s) similar or equal to 10(-5). The Standard Model is localized on a 4D IR brane. The graviton and radion Green's and spectral functions have a continuum of states with a TeV mass gap, and isolated poles consisting of the 4D graviton and the light radion/dilaton. We construct the effective field theory below the mass gap where the continua of KK modes are integrated out, generating a set of dimension eight operators which contribute to low-energy electroweak precision observables, and high-energy violation of unitarity in vector boson scattering processes. The radion mass depends on the stabilizing UV brane potential and its wave function is localized toward the IR which enhances its coupling with the SM fields. 2021-09-27T06:43:56Z 2021-09-27T06:43:56Z 2021 info:eu-repo/semantics/article Megías, E., Quirós, M. The continuum linear dilaton. Acta Physica Polonica B, Vol. 52 (2021), No. 6 – 7, pp. 711-743. DOI:[10.5506/APhysPolB.52.711] http://hdl.handle.net/10481/70438 10.5506/APhysPolB.52.711 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Jagiellonian University Press