Kvarkins

Kvarkins are a hypothetical class of elementary fermions proposed in extensions to the Standard Model of particle physics. They are envisioned as spin-1/2 particles that carry a new quantum number, the kvark charge, and participate in a new strong-like interaction mediated by gauge bosons called kvons. In such models, kvarkins come in three generations, mirroring the flavor structure of quarks, and they have corresponding antiparticles.

Kvarkins would form bound states with themselves and with standard quarks, leading to composite states tentatively called kvark-hadrons. The introduction of the new interaction allows a rich spectrum, including meson- and baryon-like states in the hidden sector, some of which might be stable and contribute to dark matter or serve as portals between the visible and hidden sectors through mixing with standard model particles.

Phenomenology: If present, kvarkins would be produced at high-energy colliders mainly via their strong-like production mechanisms, and would decay into jets and possibly leptons, depending on couplings. They would be constrained by flavor, electroweak precision, and astrophysical observations. So far there is no experimental evidence for kvarkins; collider searches have set lower mass limits in the TeV range for various coupling scenarios.

Status and outlook: Kvarkins remain a speculative concept within certain grander frameworks, such as models with extended color symmetries or hidden sectors. Future experiments at higher-energy colliders and precision measurements could probe relevant parameter spaces.