A "composite" scalar-vector system at the LHC

TL;DR

This paper investigates a combined scalar and vector resonance model at the LHC within a strong dynamics framework, analyzing unitarity constraints, production cross sections, and potential collider signatures.

Contribution

It introduces a model with both a scalar and a vector resonance below 4πv, studying their interactions, unitarity constraints, and collider phenomenology in a unified effective Lagrangian approach.

Findings

Unitarity constrains the model to two free parameters for given masses.

Numerical cross sections for Vh production via VBF and Drell-Yan are provided.

Predicted rates for same-sign di-lepton and tri-lepton events from Vh decays.

Abstract

In the framework of a strong dynamics for Electro-Weak Symmetry Breaking (EWSB), both vector and scalar degrees of freedom have been studied in the literature within an effective Lagrangian approach. Here we consider the case in which both a scalar, $h$, and a vector, $V$ - respectively an iso-singlet and an iso-triplet under a custodial SU(2) - are relevant with a mass below the cut-off $\Lambda \approx 4\pi v$. We study the amplitudes for the processes $W_L W_L \to W_L W_L, hh, V_{L}V_{L}, V_{L}h$. Requiring unitarity for the elastic channel $W_L W_L \to W_L W_L$ we can reduce the parameter space to two free parameters for given masses of the heavy vector and the scalar. We study the numerical total cross sections for the associated productions $pp\to Vhjj$ by Vector Boson Fusion (VBF) and $pp\to Vh$ by Drell-Yan (DY) annihilation as functions of these free parameters. The expected rates of same-sign di-lepton and tri-lepton events from the decay of the $Vh$ final state are also given.