If glouns interact with each other or itself, could there be a multiple glouns orbiting each other?
You appear to be describing a hypothetical composite particle most commonly called a "
glueball" (although as
@Reggid correctly explains, it is really a bit more complicated than multiple gluons orbiting each other). As the linked Wikipedia article's introduction explains:
In
particle physics, a
glueball (also
gluonium,
gluon-ball) is a hypothetical composite
particle. It consists solely of
gluon particles, without valence
quarks. Such a state is possible because gluons carry
color charge and experience the
strong interaction between themselves. Glueballs are extremely difficult to identify in
particle accelerators, because they
mix with ordinary
meson states.
Theoretical calculations show that glueballs should exist at energy ranges accessible with current
collider technology. However, due to the aforementioned difficulty (among others), they have so far not been observed and identified with certainty, although phenomenological calculations have suggested that an experimentally identified glueball candidate, denoted
, has properties consistent with those expected of a
Standard Model glueball.
The prediction that glueballs exist is one of the most important predictions of the Standard Model of particle physics that has not yet been confirmed experimentally. Glueballs are the only particles predicted by the Standard Model with total angular momentum (J) (sometimes called "intrinsic spin") that could be either 2 or 3 in their ground states.
Mathematically, they have been well described from the earliest days of
Quantum Chromodynamics (QCD), which is seemingly easy since their properties are almost entirely derived from only one experimentally determined physical constant, the strong force (i.e. SU(3)) coupling constant. All of their properties are relatively easily discerned from first principles compared to other hadrons.
But, no one has ever observed a free glueball (or, at least, has never been able to prove that what they are observing is a free glueball), although some
scalar mesons and
axial vector mesons may be a mix of glueball and non-glueball hadron states.
The lack of experimental detection of glueballs, despite the fact that they are expected to have relatively modest masses in their ground states (on the order of 0.5 GeV to 3 GeV, the same mass range as many ordinary hadrons that are observed every day at even fairly low energy particle colliders), and despite the fact that they are completely described theoretically (creating a very specific experimental target to look for), after basically half a century of looking for them, also leaves open that possibility that the actually don't exist for some subtle reason beyond the equations and physical constants of Standard Model QCD.
PeterDonis said:
Gluons are massless, so they can't orbit each other.
The other points are correct, but gravity is not the only force that can cause things to orbit other things (e.g., electrons are bound to atomic nuclei by electromagnetism rather than gravity), and gravity acts of mass-energy not just mass. "Orbit" may be a bit of an oversimplification in both the electromagnetic and strong force cases, but the presence or lack of an orbit doesn't follow from the absence of rest mass.
For example, massless photons orbit black holes when they are in what is called the
photon sphere of a black hole.
Indeed,
most of the mass of ordinary matter in the universe is derived from the energy of gluons (or gluon fields, depending upon the theoretical context you are describing them with) within in protons and neutrons, not predominantly from the valence quarks, or even from the sea quarks. Energy confined in space is basically indistinguishable from mass for purposes of general relativity.
Could this orbit create acceleration, and mass, and create quarks? Or possibly more gluon mass?
The math involved in applying QCD to real life phenomena is too difficult to do completely on an analytical basis for an exact and complete solution. Instead, what physicists do is approximate strong force interactions using a variety of different tricks. In the low energy (i.e. infrared) context, such as protons and neutrons at rest, a numerical approximation tool called "lattice QCD" is used. In the high energy (i.e. ultraviolet) context, such as particles colliding at high energies in colliders, various techniques that make up "perturbative QCD" are used.
In certain kinds of perturbative QCD approaches such as the
Nambu-Jona-Lasinio model, it is useful to think of gluons as dynamically acquiring mass for purposes of doing calculations regarding how strong force dominated systems in the perturbative QCD domain behave, even tough they have zero rest mass. See, e.g.,
this paper. The extent to which this mathematical tool corresponds to something physically real is debatable, and is, to some extent, more of a philosophical issue than a practical one, which physicists of the "shut up and calculate" school are inclined to think of as not worth answering or ill defined.
