Heavy quark signals from radiative corrections to the $Z^{\prime}$ boson decay in 3-3-1 models

TL;DR

This paper calculates one-loop radiative corrections to the $Z^{\u2019}$ decay in 3-3-1 models, revealing significant oblique and vertex correction effects that impact decay widths and collider cross sections.

Contribution

It provides the first detailed analysis of one-loop radiative corrections to $Z^{\u2019}$ decay in 3-3-1 models, including the effects of heavy quarks and gauge bosons on decay widths and collider signals.

Findings

Oblique corrections can reach up to 10.5% in neutrino channels for $m_J=2$ TeV.

Vertex corrections contribute up to 1.4% to the decay width.

Radiative corrections can increase collider cross sections by up to 23% for dielectron events.

Abstract

One-loop corrections to the $Z^{\prime}$ decay width are derived and analyzed in the framework of the general form of the 3-3-1 models. We identify two important sources of corrections: oblique corrections asociated to the $Z^{\prime}$ propagator through vacum polarizations induced by virtual particle-antiparticle pairs of new heavy quarks $J$, and vertex corrections to the $Z^{\prime}q\bar{q}$ vertex through virtual exchange of new $K^{Q_{1,2}}$ gauge bosons. Fixing an specific renormalization scheme, we obtain dominant oblique corrections that exhibit a quadratic dependence on the $J$ quark mass, which are absorbed into two oblique parameters: a global parameter $\rho ^{\prime}_f$ which modify the $Z^{\prime}$ decay width, and a parameter $\kappa ^{\prime}_{f}$ that define effective $Z^{\prime}$ couplings. Numerical results in an specific 3-3-1 model gives a strong contribution of the oblique corrections from about 1.3% in the $d(s)$ quark channel to 10.5% in the neutrino channel, for $m_{J}=2$ TeV. The vertex corrections contribute to the oblique corrections up to 1.4% for the same channel and $m_{J}$ value. For $pp$ collisions at the CERN LHC collider, we find that the corrections significantly modify the shape of the cross section distributions for $e^{+}e^{-}$ and $t\bar{t}$ final states, where the distributions including the radiative corrections increases up to 1.23 times the tree-level distribution for the dielectron events and to 1.07 for the top events when $m_{J}=3$ TeV.