Quarkdiquark

Quark-diquark is a hypothetical composite particle proposed as a potential explanation for some observed phenomena in particle physics. The concept suggests that a diquark is a bound state of two quarks, and that this diquark can then bind with a single quark to form a quark-diquark state. This three-body system would then behave as a single baryon.

The idea of diquarks has been explored in various theoretical frameworks, including quantum chromodynamics (QCD) and its effective models. Diquarks are often considered to be color-neutral, meaning they do not possess a net color charge, which allows them to combine with single quarks to form color-neutral baryons. This color neutrality is a key feature that distinguishes them from simpler quark-antiquark mesons or three-quark baryons.

While diquarks are not directly observed as free particles, their existence has been inferred as an internal structure within baryons. The quark-diquark model offers a simplified picture of baryon structure that can be useful for certain calculations and theoretical investigations. It can provide insights into baryon properties, such as their mass spectra and decay modes.

The experimental evidence for diquarks, and consequently for quark-diquark states, remains indirect and is a subject of ongoing research and debate within the particle physics community. Different theoretical models make varying predictions about the properties and observability of these hypothetical entities.