The Radion as a Harbinger of Deca-TeV Physics

TL;DR

The paper suggests that a light radion scalar predicted by warped extra-dimensional models could be detectable at the LHC, providing clues to physics beyond the Standard Model at the deca-TeV scale.

Contribution

It proposes that a radion with a mass of a few hundred GeV could be observed at the LHC, indicating new physics near 10 TeV in warped models of flavor.

Findings

Radion could be accessible at LHC with 14 TeV and 100 fb^-1

Radion mass is a few hundred GeV and inverse coupling around 10 TeV

Detection of radion could signal proximity to deca-TeV physics

Abstract

Precision data generally require the threshold for physics beyond the Standard Model to be at the deca-TeV (10 TeV) scale or higher. This raises the question of whether there are interesting deca-TeV models for which the LHC may find direct clues. A possible scenario for such physics is a 5D warped model of fermion masses and mixing, with Kaluza-Klein masses m_KK ~ 10 TeV, allowing it to avoid tension with stringent constraints, especially from flavor data. Discovery of a Standard-Model-like Higgs boson, for which there are some hints at ~125 GeV at the LHC, would also require the KK masses to be at or above 10 TeV. These warped models generically predict the appearance of a much lighter radion scalar. We find that, in viable warped models of flavor, a radion with a mass of a few hundred GeV and an inverse coupling of order m_KK ~ 10 TeV could typically be accessible to the LHC experiments -- with sqrt(s) = 14 TeV and 100 fb^-1 of data. The above statements can be applied, mutatis mutandis, to 4D dual models, where conformal dynamics and a dilaton replace warping and the radion, respectively. Detection of such a light and narrow scalar could thus herald the proximity of a new physical threshold and motivate experiments that would directly probe the deca-TeV mass scale.