Vectorlike Confinement at the LHC

TL;DR

This paper proposes Vectorlike Confinement, a TeV-scale confining hypercolor sector with vectorlike fermions that couple to the Standard Model only through gauge interactions. By organizing hyperquarks into SM-charged species, the authors show that spin-1 hyperrho resonances mix with SM gauge bosons and predominantly decay to light hyperpions, which can be either short-lived (decaying to gauge boson pairs) or long-lived (CHAMPs/R-hadrons) depending on accidental species symmetries and nonrenormalizable decays. The resulting collider phenomenology is rich and largely flavor-blind, featuring multiple gauge-boson final states, displaced vertices, di-CHAMP and di-R-hadron signatures, and potential dark matter candidates, all while staying consistent with current experimental constraints. The framework provides a broad set of testable predictions for LHC searches and connects to broader themes such as dark matter and unification, presenting a simple yet versatile avenue to explore strong dynamics beyond the Standard Model.

Abstract

We argue for the plausibility of a broad class of vectorlike confining gauge theories at the TeV scale which interact with the Standard Model predominantly via gauge interactions. These theories have a rich phenomenology at the LHC if confinement occurs at the TeV scale, while ensuring negligible impact on precision electroweak and flavor observables. Spin-1 bound states can be resonantly produced via their mixing with Standard Model gauge bosons. The resonances promptly decay to pseudo-Goldstone bosons, some of which promptly decay to a pair of Standard Model gauge bosons, while others are charged and stable on collider time scales. The diverse set of final states with little background include multiple photons and leptons, missing energy, massive stable charged particles and the possibility of highly displaced vertices in dilepton, leptoquark or diquark decays. Among others, a novel experimental signature of resonance reconstruction out of massive stable charged particles is highlighted. Some of the long-lived states also constitute Dark Matter candidates.

Figures (6)

• Figure 1: The analogy between the structure of Vectorlike Confinement and that of the QED-QCD system. Each oval represents a set of matter fields, while each line represents an interaction, thicker lines corresponding to stronger interactions. A line ending at an oval means that the oval feels the interaction represented by the line.
• Figure 2: The resonant production of hyper-$\rho$'s and their subsequent decays to a pair of hyperpions. If the hyperpions are of the short-lived type they will decay promptly to a pair of SM gauge bosons whereas if they are of the long-lived type they will register as long-lived massive charged/colored particles.
• Figure 3: Emission of an ${\tilde{\pi}}^{0}$ in a Drell-Yan process and subsequent decay to a pair of photons is found to be consistent with low mass Higgs boson searches at LEP.
• Figure 4: The differential cross section for the pair production of CHAMPs for $\sqrt{s}=14$ TeV, $m_{{\tilde{\rho}}}=2.5~\rm{TeV}$ and $m_{{\tilde{\rho}}}=4.0~\rm{TeV}$ at the LHC. While most of the CHAMPs come from Drell-Yan processes, at high enough energies resonant ${\tilde{\rho}}$ production becomes the dominant source.
• Figure 5: The differential cross section for the pair production of R-hadrons at the LHC ($\sqrt{s}=14$) TeV for three choices of $m_{{\tilde{\rho}}}$ corresponding to an $m_{{\tilde{\pi}}_{\bf 3}}$ of 300,500 and 700 GeV. At high energies, decays of resonantly produced ${\tilde{\rho}}$ dominate the production.