  Besides the ordinary hadrons, QCD allows the existence of states in which
excitations of the gluonic field can play the role of valence particles, either
alone in a glueball, or coupled to quarks in a hybrid. So, hybrid baryons, made
of three quarks and a gluon, can a priori exist. Till now, there is no
experimental evidence for such exotic hadrons but experimental efforts are
being made to search for them at CEBAF Large Acceptance Spectrometer. In this
work, a hybrid baryon is considered as a two-body system composed of a color
octet three-quark core and a gluon, interacting via a QCD-inspired interaction.
A semirelativistic potential model is built in which the dominant interaction
is a potential simulating the flux tube confinement, and the Casimir scaling is
assumed to link interactions between triplet and octet color sources. This
picture is similar to the quark-diquark description for baryons. It is chosen
in order to take properly into account the helicity of the gluon. Only $cccg$
and $bbbg$ states are considered because the strong mass asymmetry between the
quark core and the gluon is expected to favor the formation of the core. As the
results for heavy hybrid baryons seem relevant, we consider this paper as a
proof of concept which can be extended for the study of light hybrid baryons.
