Warped/Composite Phenomenology Simplified

TL;DR

This work builds a minimal, two-site four-dimensional EFT that captures the SM plus its first TeV-scale composite excitations, offering a practical framework to study warped extra-dimensional phenomenology through partial compositeness. It analyzes how elementary-composite mixing yields SM masses, preserves SM gauge invariance, and remains consistent with precision tests, while predicting TeV-scale heavy vector and fermion resonances with characteristic decays dominated by third-generation fermions and longitudinal gauge/Higgs modes. The paper provides UV-finite estimates of Higgs mass corrections in the composite-t_R scenario and maps viable parameter space that can be probed at the LHC, highlighting experimental strategies and challenges. By exploiting the AdS/CFT correspondence and a deconstructed warped picture, it offers a tractable route to test the core ideas of warped extra dimensions and their connection to strong dynamics and partial compositeness.

Abstract

This is the first of two papers aimed at economically capturing the collider phenomenology of warped extra dimensions with bulk Standard Model fields, where the hierarchy problem is solved non-supersymmetrically. This scenario is related via the AdS/CFT correspondence to that of partial compositeness of the Standard Model. We present a purely four-dimensional, two-sector effective field theory describing the Standard Model fields and just their first Kaluza-Klein/composite excitations. This truncation, while losing some of the explanatory power and precision of the full higher-dimensional warped theory, greatly simplifies phenomenological considerations and computations. We describe the philosophy and explicit construction of our two-sector model, and also derive formulas for residual Higgs fine tuning and electroweak and flavor precision variables to help identify the most motivated parts of the parameter space. We highlight several of the most promising channels for LHC exploration. The present paper focusses on the most minimal scenario, while the companion paper addresses the even richer phenomenology of the minimal scenario of precision gauge coupling unification.

Figures (4)

• Figure 1: One-loop log divergent contribution to the Higgs mass squared from the virtual exchange of an elementary $t_R$. A circled cross denotes a $\Delta_{t_R}$ mass mixing. We used Eqs. (\ref{['R fermion mass diag']}), (\ref{['exp mass']}) to set $\Delta_{t_R} = \tilde{m}_*^T \sin\varphi_{t_R}$, and the fact that additional $\Delta_{t_R}$ insertions on the $t_R$ elementary propagator are suppressed for divergent virtual momenta.
• Figure 2: One-loop corrections to the Higgs mass squared in the minimal model with composite $t_R$ adopting the elementary/composite basis. Black squares represent resummation of all higher elementary/composite mass-mixing.
• Figure 3: Exclusion curves in the plane $(m_*,M_*)$ for $Y_{*U33}=2,2.5,3$ and $Y_{*D33}/Y_{*U33}=1/2$ (left plot) or $Y_{*D33}/Y_{*U33}=1/3$ (right plot). The area below each curve is excluded at $99\%$ CL by a combined fit to the electroweak observables $S$, $T$ and $\delta g_{Lb}$.
• Figure :